INVENSYS PROCESS SYSTEMS (S) PTE LTD DOCUMENT TITLE : Basic Of Design Document DOCUMENT NO: MD-502-7000-IN-BOD-1025-2011 REQUISITION NO: KAR 760 PURCHASE ORDER NO: 4500039280 ITEM NO: All Items ITEM DESCRIPTION: ITCC APPROVED WITH COMMENT REVIEWED RESUBMIT Thisapprovalorreviewdoesnotrelievethe vendor/subcontractorofhisresponsibilitiesto meet all requirements of the purchase order ORIGINALCHEKEDAPPD(PRJ) SIGN DATE SAMSUNG ENGINEERING CO., LTD D0304Dec2009Final (For Record)STNDDJ IY D0212May2009Revised As Per I-FAT CommentWCCMNJ IY D0123Feb2009As-BuiltWCCMNJ IY C0122Dec2008Issue for ConstructionWCCMNJ IY A0118Sep2008Issue for ApprovalSHEMNJ IY REVDATEDESCRIPTIONPREPARED BYCHECKED BYAPPROVED BY SAUDI ARABIAN MINING COMPANY(MA'ADEN) MA'ADEN AMMONIA PROJECT Worley Parsons SAMSUNG ENGINEERING CO., LTD. SEOUL KOREA SECL PROJECT NO. : SC2158 Uhde GmbH FOR RECORD INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) DocumentSG60016-TC2-TMC-BODD-10001 CustomerMD-502-7000-IN-BOD-1025-2011 Contract No.4500039280 Project No.SG60016 INVENSYS PROCESS SYSTEMS (S) PTE LTDPage3of99 PROJECT NAME : MAADEN AMMONIA PROJECT CUSTOMER NAME : SAMSUNG ENGINEERING CO. LTD ENDUSER NAME: SAUDI ARABIAN MINING COMPANY (MAADEN) LOCATION: KINGDOM OF SAUDI ARABIA Basis of Design Document 7A50-K01/7A50-K01-TS01 Synthesis Gas Compressor/Turbine D0304Dec09STNDDJIYFinal(For Record) D0212May09WCCMNJIYRevised As Per I-FAT Comment D0123Feb09WCCMNJIYAs-Built C0122Dec08WCCMNJIYIssue for Construction A0118Sep08SHEMNJIYIssue for Approval RevDatePrepdChkdAprd Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:3of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) TABLE OF CONTENTS 1GENERAL .......................................................................................................................... 5 2APPLICATION OVERVIEW............................................................................................. 7 3INTERFACE DESCRIPTION........................................................................................... 10 4SEQUENCE DESCRIPTION (7A50-K01-TS01) ............................................................ 11 4.1INTRODUCTION.................................................................................................................11 4.2MODE ASSIGNMENTS.......................................................................................................11 4.3MODE 0 TURBINE SHUTDOWN.................................................................................15 4.4MODE 1 READY-TO-START..........................................................................................16 4.5MODE 2 2ND IDLE SPEED..............................................................................................17 4.6MODE 3 ACCELERATION..............................................................................................19 4.7MODE 4 RUN...................................................................................................................20 4.8MODE 5 OVER SPEED TRIP TEST................................................................................22 5CONTROL DESCRIPTION (7A50-K01/7A50-K01-TS01)............................................ 23 5.1GENERAL ..............................................................................................................................23 5.1.1STEAM TURBINE CONTROL (7A50-K01-TS01) .................................... 23 5.1.2SPEED AND EXTRACTION PRESSURE CONTROL ................................ 23 5.1.3PROCESS/SURGE DECOUPLING......................................................... 25 5.1.4SURGE CONTROL AND THE SURGE MAP........................................... 31 5.2NAMING CONVENTION...................................................................................................35 5.3CONSTANT INITALIZATION............................................................................................37 5.4ANALOG INPUT SCALING................................................................................................37 5.5TRIPS & ALARMS................................................................................................................38 5.5.1TRIPS ............................................................................................... 38 5.5.2ALARMS........................................................................................... 39 67A50-K01/7A50-K01-TS01 CONTROL MODULE DESCRIPTION............................. 40 6.1CONTROL MODULE ASSIGNMENT...............................................................................40 6.27A50-K01-TS01 STEAM TURBINE CONTROL MODULES.........................................42 6.2.1SP1 - SPEED INPUT MEDIAN SELECT ................................................. 42 6.2.2SP2 PROCESS / SURGE DECOUPLING.............................................. 43 6.2.2.1DYNAMIC BREAKPOINT ........................................................................................................... 44 6.2.2.2GAIN ADJUSTMENT ................................................................................................................... 45 6.2.2.3PROCESS OVERRIDE................................................................................................................... 45 6.2.2.4DECOUPLING SPEED SETPOINT.............................................................................................. 46 6.2.2.5PROCESS CONTROLLER TRACKING ...................................................................................... 47 6.2.3SP3 TARGET SPEED SETPOINT........................................................ 48 Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:4of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.2.4SP4 SPEED SETPOINT RAMP........................................................... 49 6.2.5SP5 SPEED PID............................................................................... 50 6.2.6SP6 TWO VALVE ALGORITHM........................................................ 51 6.3.1PC1 EXTRACTION PRESSURE PID.................................................... 52 6.3.2PC2 1ST STAGE SUCTION PRESSURE PID ......................................... 53 6.3.3PC3 EXTRACTION BYPASS PID ....................................................... 54 6.2.7PC4 MP STEAM VENT PID .............................................................. 55 6.3SC1 ANTI-SURGE CONTROLLER ..................................................................................56 6.3.4SC1 ANTI-SURGE CONTROLLER....................................................... 56 6.3.5FLOW COMPENSATION .................................................................... 57 6.3.6OPERATING POINT........................................................................... 58 6.3.7PRESSURE RATIO.............................................................................. 59 6.3.8ANTI-SURGE CONTROLLER CONFIGURATION.................................... 60 6.3.9ANTI-SURGE VALVE AND TRACKING LOGIC...................................... 61 6.3.10 TRANSMITTER FAIL-OVER STRATEGY................................................ 62 7DUAL COIL ACTUATOR CONFIGURATION.............................................................. 63 7.1COIL STATUS FEEDBACK .................................................................................................64 APPENDIX A CONSTANT LIST......................................................................................... 65 APPENDIX B INTERFACE LIST ......................................................................................... 74 APPENDIX C ANALOG INPUT RANGES ......................................................................... 76 APPENDIX D APPLICATION DETAIL............................................................................... 77 APPENDIX E TURBINE EXPECTED PERFORMANCE CURVE....................................... 85 APPENDIX F H, F, B CALCULATION............................................................................... 86 APPENDIX G FLOW ELEMENT DATA SHEET................................................................. 87 APPENDIX H COMPRESSOR DATA SHEETS.................................................................. 91 APPENDIX J COMPRESSOR SURGE MAP....................................................................... 92 SPPENDIX K UNIVERSAL SURGE MAP .......................................................................... 96 1ST AND 2ND STAGE (OVERALL) ..................................................................................................96 3RD STAGE..........................................................................................................................................97 RECYCLE STAGE ...............................................................................................................................98 Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:5of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 1GENERAL The Basis of Design Document defines the Triconex Steam Turbine/Compressor Control System for the MA'ADEN AMMONIA Plant Project, and provides general control guidelines for Startup, Speed Control, Shutdown, and Anti-Surge Control and other control functions for 7A50-K01 Synthesis Gas Compressor provided to Samsung Engineering Co., Ltd (Hereafter referred to as SECL), for MAADEN by Invensys Process Systems (S) Pte Ltd, Triconex (Hereafter referred to as IPS). Once approved, this document forms the basis for designing this system. Relevant identification data: Customer:Samsung Engineering Co., Ltd End User:Saudi Arabian Mining Company (Maaden).Project:Ma'aden Ammonia Project System Type:TS3000 (TRICON) Location:Ras Az Zawr City, KSA For the development of the detailed design, SECL will provide IPS with the following: I/O List Field Cable Schedule P&ID Explanation of Governor Instrument Data Sheet Turbine Startup Curve Expected Performance Curve Compressor Data (Map/Curves) Complex Loop Diagram (Uhde) Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:6of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) The Triconex TS3000 (TRICON) Integrated Turbine and Compressor Control System (ITCC) is based on the Triconex Tricon Controller - a state-of-the-art fault-tolerant controller based on the Triple Modular Redundant (TMR) architecture. TMR employs three identical isolated system legs of which each leg independently executes the control program in parallel with the other two legs. This tolerates and ensures that a single point of failure will not affect the other healthy legs. The TMR system uses two-out-of-three voting architecture to ensure high integrity and reliability of the I/O signals. On-line replacement and hot sparing of the I/O modules are possible. This will eliminate any undue interrupt to the process or operation should a fault occur in the module. The entire plant is designed to be fail-to-safe mode.Therefore, the field inputs or outputs are normally in the Close or Energize state respectively when in normal condition.A logical 1 input signal to the TMR system is treated as a normal state and a 0 logic signal is treated as trip or failure state. Upon total power failure, the output signals should go to 0 state. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:7of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 2APPLICATION OVERVIEW This application provides for control of a Steam Turbine driving a four stage compressor. TS3000 (TRICON) control systems are used in the plant to allow smooth transition from one set of desired operating conditions to another set, and shall compensate for changes in dynamic performance of the plant due to changing operating conditions. In Turbine Speed Control application, the use of Mode-based sequencing instead of Event-based sequencing produces a control program that is less prone to errors, easier to trouble-shoot and easier to understand. These Modes are automatically selected depending on current operating conditions, operator demands and commands from other systems (DCS /HMI). Each mode is tightly interlocked, so the next mode can only be entered when conditions are correct. In Anti-Surge Control applications, the abilities to efficiently perform complex algorithms required by means of individual modules, produces a control program that is less prone to errors, easier to trouble-shoot and easier to understand. An individual module, each having a defined functionality, interacts with other modules to ensure that the Anti-Surge Valve opens in time to prevent surge. There are 3 Anti-Surge controllers. The compressor manufacturer's surge curves are converted to a graph of compressor pressure ratio (Pd / Ps) vs. head compensated for suction pressure (Hc %).These values are entered into the Triconex standard surge control algorithm to determine the surge point. An adjustable safety margin is added to the surge line to produce the flow set point.The flow and pressure variables are used to determine the operating point, which is compared to the control line set point. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:8of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) Please refer to Appendix J for Manufacturer Surge Curve. Please refer to Appendix K for Triconex Universal Surge Map. The compressor shall be considered in surge when the operating point is to the left of the configured surge line. An application overview is illustrated in Figure 2-1-1. Upon activating the Start pushbutton, TS3000 (TRICON) will achieve the following: Turbine Sequencing Turbine Speed Control Extraction Control (MP Header) Compressor Performance (1st Stage Suction Pressure) Control Anti-Surge Control TS3000 (TRICON) will also perform the following: Alarming and Tripping Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:9of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 7A50-K017A50-K01-TS017A50-SV-5001AGV3 x Speed Pickup7A50-SE-5001A/B/CCondenser1st Stage 2nd StageTT5011PT50117A50-FXV-5012To 7A50-E14To 7A50-E13From Drying Uni t Filters7A50-V017A50-K017A50-SV-5001BEVTT5014PT5014FT5012Recycle Stage7A50-K01PT5018FT5014TT5018TT5017PT50177A50-FXV-50143rd Stage7A50-K01PT5016TT5016FT50137A50-FXV-5013PT5015TT5015FT5002PT5003APT5003BExtraction To MP Steam HeaderSynthesis Gas Compressor Figure 2-1Application Overview (Surge and turbine control) Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:10of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 3INTERFACE DESCRIPTION The Triconex TS3000 (TRICON) system provides control for the start-up of the Turbine through, HMI (Local) and DCS (Remote). The Remote/ Local Selection can be selected from HMI (f7A50REMLOC). Remote/Local status indication will be in HMI and DCS.In Local mode, Operator can issue command from HMI, and when in Remote from DCS. Please refer to Appendix B for Interface List. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:11of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 4SEQUENCE DESCRIPTION (7A50-K01-TS01) 4.1INTRODUCTION This section defines the control implementation in the TS3000 (TRICON) Synthesis Gas Compressor - Steam Turbine (7A50-K01-TS01), and discusses the following: Sequence Modes Description of the sequential operation 7A50-K01-TS01 Steam Turbine Control Description 4.2MODE ASSIGNMENTS The TS3000 (TRICON) Startup/ Shutdown Sequence is organized into a series of Modes or states defining the progressive stages of the turbine startup and any special considerations involved with the execution of a given Mode.Each defined Mode is assigned a sequential number used within the TS3000 (TRICON) logic. The sequence logic decides which Mode may be entered from the current Mode. This ensures an orderly progression through the Modes and appropriate actions in the event of an operational change. The sequence mode variable i7A50MODE defines the various starting, operating, and test Modes that control the program. The sequence of operation for the 7A50-K01-TS01 Steam Turbine Control System for Synthesis Gas Compressor will be determined by these modes. ModeDescription Mode 0Turbine Tripped/Shutdown Mode 1Ready to Start Mode 22ND Idle Speed (1500 RPM) Mode 3Acceleration (7828 RPM) Mode 4Run (7828-10274 RPM) Mode 5 Over Speed Trip Test Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:12of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) Refer to Figure 4-2-1, 7A50-K01-TS01 Steam Turbine Start-up Sequence. Refer to Figure 4-2-2, 7A50-K01-TS01 Steam Turbine Start-up Curve. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:13of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) Figure 4-2-17A50-K01-TS01 Steam Turbine Start-up Sequence Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:14of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) Figure 4-2-27A50-K01-TS01 Steam Turbine Start-up Curve Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:15of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 4.3MODE 0 TURBINE SHUTDOWN Entered From ConditionRemarks Any ModeWhenever the turbine is tripped. If the Trip has not been reset, the TS3000 (TRICON) will remain in Mode 0, Shutdown.It will be prevented from starting until all trip conditions have been cleared and the system has entered Mode 1, Ready-to-Start. Refer to Table 5-5-1 for list of Trip signals InitialWhen TS3000 (TRICON) is powered up. In this Mode: Action The Speed Controller output is clamped to 0%. The minimum and maximum limits on the Governor Valve are set to 0 %. The Actual Speed Setpoint and Target Speed Setpoint are set to 0 RPM. The minimum and maximum limits on the Actual Speed Setpoint are set to 0 RPM. The minimum and maximum limits of Extraction Valve are set to 0 %. Anti-Surge Control is disabled and placed in Partial Manual. The Anti-Surge Valve is forced to 100% open. Common Trip Signal will be sent to DCS/HMI/ESD. Any of the Anti-Surge Valves can be stroked by placing the controller in Full Manual provided speed is less than 50 RPM. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:16of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 4.4MODE 1 READY-TO-START Entered From ConditionRemarks Mode 0 Shutdown All trips are cleared and reset from DCS Refer to table of Start-up Permissive below In this Mode: Action Performance Controller is disabled and sent to DCS/ HMI. Ready to Start Signal will be sent to DCS/ HMI.The minimum and maximum limits of the Actual Speed Setpoint are set to 0. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:17of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 4.5MODE 2 2ND IDLE SPEED Entered From ConditionRemarks Mode 1Ready to Start A Start Command from HMI (Local) / DCS (Remote) is issued.The turbine is started manually. Trip and throttle valve will be opened gradually by operator.Operator will warm-up the turbine at approximately, the 1ST Idle Speed (700 RPM) for around 36 minutes as per the startup procedure (it depends on the start-up conditions) After the warm-up at 1ST Idle Speed is completed, operator may proceed to fully open the T&T Valve. TS3000 (TRICON) will control the speed at 2ND Idle Speed (1500 RPM) with V1. The turbine will be allowed to run at 2ND Idle speed for around 36 minutes as per the startup procedure. NOTE: If the turbine speed increases above 1500 RPM, the Governor Valve, V1 will throttle and take control of the speed. Warm-up Timers are for indication only. Mode 3Acceleration Idle Speed Command from DCS/HMI is issued and turbine speed is between 2ND Idle Speed and Min. Governor Speed. The turbine speed will decrease to 2ND Idle speed. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:18of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) In this Mode: Action The Peak Speed Recorder is reset and begins recording maximum speed.Trip Speed Recorder is reset. All Anti-Surge Controllers are placed in Partial Manual. All Anti-Surge Valves are forced to 100% open. The minimum and maximum limits of ECV (V2) are ramped to 100% (1%/Sec). The Actual Speed Setpoint is clamped between 0 and Minimum Governor Speed (7828 RPM). The Target Speed Setpoint is set to 2ND Idle Speed (1500 RPM). The Actual Speed Setpoint is ramped towards the target at normal ramp rate (500 RPM/min).Countdown timers are reset. 1ST Idle Speed Countdown Timer is started once 650 RPM is reached.The count down stops any time the speed drops below 600 RPM or rises above or equal to 750 RPM.2ND Idle Speed Countdown Timer is started once 1450 RPM is reached.The count down stops any time the speed drops below 1400 RPM or rises above or equal to 1550 RPM. Both timers are for indication only. Start-up speed tuning parameters for the Speed Controller are used. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:19of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 4.6MODE 3 ACCELERATION Entered From ConditionRemarks Mode 2Idle Speed A Minimum Governor Command from DCS/HMI is issued and turbine speed is within 50 RPM of 2ND Idle Speed Turbine will be brought to Min. Governor Speed. In this Mode: Action The Target Speed Setpoint is set to Min. Governor Speed (7828 RPM). The Actual Speed Setpoint is ramped to the target at normal ramp rate (500 RPM/MIN). During Critical Speed Band (2468 4620 RPM), the Actual Speed Setpoint is ramped towards the target at fast ramp rate (2000 RPM/MIN). The operator can press the speed Halt pushbutton from DCS/ HMI provided the Actual Speed Setpoint and Actual Speed are not in the Critical Speed Band. This will cause the turbine sequence to stop. The Target Speed Setpoint will be set to the current Actual Speed Setpoint. The operator can now raise or lower the Target Speed Setpoint from DCS/ HMI. The turbine sequence continues when operator presses speed Continue pushbutton from DCS/HMI. An indication will be sent to DCS/ HMI when actual speed is in the Critical Speed Band. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:20of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 4.7MODE 4 RUN Entered From ConditionRemarks Mode 3 Acceleration Actual speed reaches 50 RPM below the Minimum Governor Speed (7828 RPM). This is the normal on-line operating Mode.Mode 5 Over Speed Trip Test An Over Speed Trip Test Off command from HMI is issued. In this Mode: Action The Actual Speed Setpoint is clamped between Minimum Governor Speed (7828 RPM) and Maximum Governor Speed (10274 RPM). The Anti-Surge Controllers are enabled and automatically placed in the Auto Mode. The Anti-surge Valves will start closing if required. The Anti-surge Controllers can be placed in Auto or Partial Manual Mode.The Performance Control can be enabled or disabled from HMI. The Extraction Steam Pressure Control can be enabled or disabled from HMI. To enable the Extraction Steam Pressure Control, lower the Extraction Valve Min Limit to 0% by pressing the V2 Min. Limit Lower button on the HMI. To disable the Extraction Steam Pressure Control, raise the Extraction Valve Min Limit to 100% by pressing the V2 Min. Limit Raise button on the HMI.When the Extraction Steam Pressure Enable LED on the HMI blinks in Grey, it means that the Extraction Steam Pressure Control is not fully disabled. When the Extraction Steam Pressure Enable LED on the HMI blinks in Green, it means that the Extraction Steam Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:21of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) Action Pressure Control is not fully enabled.If 7A50-X-GT signal is active, the Target Speed Setpoint is set to Minimum Governor Speed (7828 RPM). The Actual Speed Setpoint is ramped to the target at normal ramp rate (500 RPM/MIN). The Anti-surge Controllers are disabled and the Anti-surge Valves are forced to 100% open. The Performance Control will be disabled. The minimum limit on ECV (V2) will ramp to 100% open, and thus disabling Extraction Steam Pressure Control. The Over Speed Trip Test can be enabled or disabled from HMI. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:22of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 4.8MODE 5 OVER SPEED TRIP TEST Entered From ConditionRemarks Mode 4 Run Over Speed Trip Test from HMI is switched to EOST or MOST In this Mode: Action Over Speed Test indication will be sent to DCS/ HMI. Performance Control is disabled. The minimum limit on ECV (V2) is ramped to 100% (1%/Sec) and ECV (V2) will be fully open. Extraction Steam Pressure Control will then disable. All Anti-Surge Controllers are disabled and the valves are forced to 100% open. The Actual Speed Setpoint high limit is changed to 11500 RPM IF EOST is selected: Turbine trips at EOST trip setpoint of 11198 RPM, when the speed is increased from HMI/ DCS. The turbine will be tripped by the Protech at 11302 RPM if the EOST fails to trip the turbine. IF MOST is selected: Governor Overspeed trip setpoint automatically changes to 11320 RPM. Turbine trips at Protech trip setpoint of 11302 RPM, when the speed is increased from HMI/ DCS. The turbine will be tripped by EOST at 11320 RPM if the Protech fails to trip the turbine. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:23of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 5CONTROL DESCRIPTION (7A50-K01/7A50-K01-TS01) 5.1GENERAL 5.1.1STEAM TURBINE CONTROL (7A50-K01-TS01) During normal operation, the compressor 1ST stage suction pressure control loop sets the demand to the Decoupling block. The Decoupling block then sets the correct speed setpoint when performance controller is enabled. The speed controller output sets the steam inlet valve position command to regulate turbine speed. 5.1.2SPEED AND EXTRACTION PRESSURE CONTROL Under normal conditions, the steam inlet valve, V1, will move to control turbine load (speed) and the extraction valve, V2, will move to control extraction pressure. When limiting conditions are active, speed control is set as the priority. The limiting conditions include when valves are fully extended or retracted and turbine has hit its load limits. Turbine speed and extraction pressure are affected by movement of either valve, V1 and V2. To maximize process stability, valve action is managed by a two-valve coordination function. This function minimizes the process interaction from individual valve movement and permits dynamic speed and extraction pressure control loop tuning. The MP steam header pressure is maintained by the actions of the bypass valve, extraction valve and vent valve of Synthesis Gas Compressor (SGC), and the bypass valve and extraction valve of Refrigeration Compressor (RGC). The SGC extraction pressure controller setpoint shall act as the master MP steam header pressure setpoint. The SGC bypass controller shall have its setpoint set at master setpoint less 50kPa and the SGC vent controller shall have its setpoint set at master setpoint plus 100kPa. The RGC extraction controller setpoint shall be set at Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:24of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) master setpoint plus 50kPa. During normal operations, the SGC bypass valve shall be fully closed, the SGC extraction valve shall be fully open, and the RGC extraction valve shall act to maintain the MP steam header pressure between the SGC extraction controller setpoint and RGC extraction controller setpoint. If the MP steam header pressure rises above the vent controller setpoint, the vent valve shall open to bleed off steam, and thus preventing an excessive pressure build-up in the MP steam header. In the event of SGC turbine trip, the SGC bypass valve shall open to maintain the MP steam header pressure by restoring the lost SGC extraction flow. The SGC bypass controller shall switch to Manual and its manual demand shall be calculated by adding its output and the SGC extraction flow percentage right before the SGC turbine trips. In the event of RGC turbine trip, the RGC bypass valve shall react to restore the lost RGC extraction flow. The RGC bypass controller shall switch to Manual and its manual demand shall be calculated as the RGC extraction flow percentage right before the RGC turbine trips. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:25of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 5.1.3PROCESS/SURGE DECOUPLING The control of Synthesis Gas Compressor is accomplished using Triconex Turbo machinery Control System (TS3000) that controls the suction pressure by manipulating the speed of the compressor and the Anti-Surge Valve. Historically, suction pressure has been controlled by the compressor speed while the Anti-Surge Valve controlled the surge. Unfortunately, this can lead to fighting between the surge controller and the suction pressure controller, ultimately leading to unstable compressor operation. To avoid this operating scenario, Triconex uses an approach called process / surge decoupling. This approach decouples the suction pressure controller from the surge controller by ensuring that different controllers are not adjusting the Anti-Surge Valve and the compressor speed simultaneously. The way the decoupling function prevents the two controllers from fighting is by trying to prevent the surge controller PV from ever decreasing below the surge controller setpoint, and therefore preventing the surge controller from controlling the Anti-Surge Valve. To accomplish this it allows the suction pressure controller to open the Anti-Surge Valve of the Compressor. By opening the Anti-Surge Valve, process gas is brought back to the suction of the compressor and the contribution of the first stage to the forward flow is decreased, and at the same time the flow through the suction of the compressor is increased. In this way the pressure controller can control suction pressure by using the Anti-Surge Valve. The decoupling function manages and decides when the suction pressure controller should be manipulating the speed or manipulating the Anti-Surge Valve. This is done with split range control that can either control the suction pressure with the compressor speed or the Anti-Surge Valve position but not both simultaneously. What is unique about this split range is that the point at which the suction pressure controller switches between using the speed orProject Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:26of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) The Anti-Surge Valve is variable. We call this variable split point the Dynamic Breakpoint. For example, as the feed to the compressor decreases, the suction pressure controller decreases the compressors speed in order to maintain the same suction pressure. Prior to reaching a point where lowering the compressor speed will cause the surge controller to open the Anti-Surge Valve (because reducing speed at a constant differential pressure will eventually drive the compressor into surge), the decoupling block will let the suction pressure controller open the Anti-Surge Valve, therefore preventing the surge controller from taking control of the Anti-Surge Valve and maintaining pressure control through the Anti-Surge Valve. The behavior of the dynamic breakpoint under normal operation (which is an operating point that is to the right of the Maximum Zone line) is to stay a given distance below the output of the pressure controller. By operating this way, the compressor will operate on the speed control side of the decoupling algorithm instead of on the Anti-Surge Valve. We call this distance the dynamic breakpoint hover margin. The dynamic breakpoint is ramped in the following manner. If the operating point is to the right of the Maximum Zone Line and to the left of the Fast Breakpoint line (a preset distance from the Surge Control line that determines whether the Dynamic Breakpoint moves slow or fast), it will be ramped down at a relatively slow predetermined ramp rate. The ramp rate for the Dynamic Breakpoint is slow in this region because the compressor is operating fairly close to the surge control line at this point and will not be able to slow down much more without interacting with Anti-Surge controller. Therefore, it makes sense to slow the compressor down at a lower rate, as the suction pressure controller will likely have to start working on the Anti-Surge Valve if the suction pressure continues to fall. If the operating point is to the right of the Fast Breakpoint line, it will be ramped down at a relatively fast ramp rate. This is because the compressor has a lot of speed it can give up in this region before it gets close to the surge control line. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:27of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) If the operating point is to the left of Minimum Zone line, it will be ramped up at predetermined slow ramp rate. The intent of increasing the speed of the compressor in this operating region on the surge map is to use the inventory that has accumulated in theProject Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:28of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) system to increase the suction flow and keep the compressor away for interaction with the Anti-Surge controller. Since increasing the speed will also lower the suction pressure, the suction pressure controller will open the Anti-Surge Valve to increase the suction pressure. These actions, taken together, should push the compressor away from the surge control line.If the operating point is in between the Minimum Zone line and the Maximum Zone line, the Dynamic Breakpoints position is fixed at the position it was located at when the operating point entered that region. It is important to remember that the position of the Dynamic Breakpoint is (in most cases) a function of the compressor operating point location on the surge map. The only exceptions to this are scenarios 1 and 2 as defined above. The distance that the Dynamic Breakpoint operates to the left of the pressure controller output is configurable but is generally ~1.5% below the controller output. This ensures that the suction pressure controller will be operating on the speed controller whenever possible. If the pressure controller output decreases faster than the dynamic breakpoint is allowed to ramp down (based on the operating region), the pressure controller will use the Anti-Surge Valve to control the suction pressure. The illustration below shows the different regions of operation on the surge map. There are also three examples of different Decoupling Algorithm scenarios. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:29of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) S urge line C o m p e n s a t e d F l o wS urge control lineP dP sM I N I M U MZ o n eM A X I M U MZ o n eF as t B reakpoint line Figure 5-1-3-1 Surge Map 100%100%0%0%min governormax governorPressure controller output75% =0% surge valve and 50% of speed rangeDynamic Breakpoint=Operating point minus Breakpoint Hover Marginnote: the surge valve line slides with the dynamic breakpointBreakpoint hover marginSPEED SETPOINTKICKBACK VALVEoperating point Figure 5-1-3-2 Example 1 Example 1 displays normal operation for the compressor. In this scenario, the suction pressure of the compressor is being controlled by the speed of the compressor and the Dynamic Breakpoint is operating just below the output of the suction pressure controller. If the output of the pressure controller were to drop more quickly than the Dynamic Breakpoint can moveProject Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:30of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) (based on the position of the operating point relative to the surge map as discussed above), the suction pressure controller would stop reducing the speed and instead control the suctionpressure using the Anti-Surge Valve. Assuming the operating point is still greater than the Maximum Zone line, the Dynamic Breakpoint would continue to reduce its output (and consequently the operating speed of the compressor) to get back to its original Breakpoint Hover margin below the operating point. This reduction in speed would cause the Anti-Surge Valve to close. 100%100%0%0%min governormax governorPressure controller output25% =50% surge valvedynamic breakpointSPEEDSETPOINTKICKBACKVALVEoperating point Figure 5-1-3-3Example 2 Example 2 shows the operation of the compressor using the Anti-Surge Valve to control the suction pressure. In this case, the compressor load has dropped to a point that the speed is running at minimum governor. The compressor will continue to operate in this region until the load is increased. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:31of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 100%100%0%0%min governormax governorPressure controller output50% =0% surge valve and min govdynamic breakpointSPEEDSETPOINTKICKBACKVALVEOperating point Figure 5-1-3-4 Example 3 Example 3 shows the compressor operating at minimum governor and either closing off or opening up the Anti-Surge Valve to control the suction pressure. If load is being added, the Anti-Surge Valve will close and the speed will start to increase to take up the additional load. As the speed increases, the Dynamic Breakpoint will follow the operating point to a scenario similar to Example 1. If the load is being decreased, the Dynamic Breakpoint will stop at minimum governor and the Anti-Surge Valve will open to control the suction pressure. This will lead to a scenario similar to example 2. 5.1.4SURGE CONTROL AND THE SURGE MAP As per discuss above, the surge controller is a separate controller from the suction pressure controller. Its function is to ensure that the stage or stages that it is protecting have enough flow for the current operating conditions to prevent surge. It does not control any pressures. It uses a number of equations and inputs to calculate an operating point (see the detailed sections of this document on surge controllers). The surge controller has several features to help protect the compressor from surge. The figure below shows the surge map and how the surge controller measures distance to the surge line. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:32of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) Figure 5-1-4-1 Head Compensated for Suction Pressure The setpoint of the surge controller tracks the operating point much like the dynamic break point tracks the output of the pressure controller. This setpoint will try to maintain a given distance from the operating point (hover margin, usually about 5%) with certain restrictions. It is not allowed to go to the left of the constant safety margin or more than 20% to the right of the constant safety margin. It also must ramp down at a given ramp rate (hover ramp). Since the setpoint hover line is the setpoint of the surge controller, if the operating point moves quickly towards surge, the surge controller will respond prior to the operating point crossing the constant safety margin due to the ramp on the setpoint hover line. This will allow the surge controller to act earlier on a process upsets that might cause a surge event. If the operating point stabilizes to the right of the constant safety margin the surge controllers output will decrease as the setpoint ramps back to the left of the operating point. In addition to the normal PID surge controller, the surge controller also has a surge override function that will ensure that the Anti-Surge Valve opens in the event that the compressor is Actual Surge Line Hc Pd Constant safety margin Surge control line Ps Controller PVSurge override region with setpoint equal to constant safety margin Setpoint Hover Margin Setpoint hover line Operating point Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:33of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) approaching surge. This is useful because the normal surge control PID will most likely be tuned too slowly to prevent compressor surge caused by a large process upset. The surgeoverride function opens the Anti-Surge Valve as the operating point moves into the proportional action region (see figure below). The valve opens in direct proportion to the distance across this region that the operating point has traveled. If the margin reaches 0 or crosses the Surge Line, the proportional term reaches its maximum limit (the Anti-Surge Valve is 100% open). The proportional action region increases and decreases in size relative to the movements of the setpoint hover line. Therefore, as the setpoint hover line moves to the right of the surge map (in response to the movement of the operating point), the proportional action region will spread out because the region is defined as a portion of the total distance between the surge line and setpoint hover line. The surge override output is high selected with the normal surge PID controller and will therefore only be in control if (as stated above) the PID is responding too slowly. The surge PID tracks the output of the override controller if the override output is greater than the PID output. Surge override output 0% Closed Open Surge line Hc PdThis range is a percentage (typically about 70% of the span) of the total distance from the Surge line to Setpoint Hover line. Setpoint hover line 100% Ps Proportional action region Figure 5-1-4-2 Surge Override Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:34of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) The Surge control PID and the surge override output are sent to the Anti-Surge Valve selection block. For the low-pressure stage of the compressor this block combines these outputs with the decoupling Anti-Surge Valve output for high selection. This block makes the surge PID track if the decoupling block is in control of the Anti-Surge Valve. This prevents any time delays that would be caused by the surge PID winding down. It also restricts the movements of the Anti-Surge Valve opening and closing. Triconex calls these restrictions slew rates. The closing rate is typically very slow to ensure stability as the Anti-Surge Valve is closed. This is often seen when the compressor load is being increased as the Anti-Surge Valve will be limited in how quickly it can close by the surge PID controller. In this situation, the suction pressure controller (Decoupling Algorithm) will momentarily increase the speed of the compressor (in response to the load increase) while it waits for control of the Anti-Surge Valve to be returned to the suction pressure controller from the surge PID controller. When control is returned, it will stop increasing speed and again work on closing off the Anti-Surge Valve. The Anti-Surge Valve control will continue to be handed off between the suction pressure controller and the surge PID controller until the valve is finally closed and the compressor is on pressure control (assuming that the required compressor speed is above minimum governor). The opening slew rate is to prevent overshoot when the surge override function comes in as the surge override function can increase at a rate much faster than the valve (and the corresponding process) can respond. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:35of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 5.2NAMING CONVENTION A summary of the field device and signal tag prefix convention is included for reference.All I/O are in a general format of xAAAA, where: x is a small cap prefix, which refers to the I/Os signal type AAAAA refer to the I/Os Tagname Naming convention for I/O signal type x Hardwired Signals: PrefixSignal wAnalog Inputs yUnscaled Analog Outputs tThermocouple Inputs dDigital Inputs cDigital Outputs pPulse Inputs Memory Signals: PrefixSignal fDigital Memory mDigital Memory AlarmgDigital Memory Enterable iAnalog Memory Integer rAnalog Memory Real eAnalog Memory Enterable kConstant Memory All Alarm/Trips are in a general format of mAAAA_FO, where: m is a small cap prefix, which refers to the I/Os signal type AAAA refer to the I/Os Tagname Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:36of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) FO is a capital suffix, which refer to First out flag. Example: mTBA - Common shutdown to DCS mTBA_FO - First out Alarm kNORRR - Actual Speed Setpoint Normal Ramp Rate kFASTRR Actual Speed Setpoint Fast Ramp Rate Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:37of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 5.3CONSTANT INITALIZATION Constant initialization passes the constant values to the tags which are defined in the logic. These constant values are passed during the first scan of TS3000 (TRICON) operation. Please refer to Appendix A for tags and their values in the Constant List. 5.4ANALOG INPUT SCALING All analog inputs are scaled and any square rooting or filtering is performed (as required). It will also perform signal selection (HI, LOW, Mid-selects or any averaging). Alarms that are based on input values or failures are also generated. If fallback or safe values are associated with inputs these values will reside in the appropriate module related to that control function. Analog inputs that have exceeded the allowable range of 3.2 mA and 21.6 mA will have their respective failure flags set false. If an analog input fails, it will remain failed unless it returns to the acceptable range and remains in this range for a period of five minutes. Please refer to Appendix C for Analog Input Ranges.Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:38of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 5.5TRIPS & ALARMS 5.5.1TRIPS The following conditions trip the turbine: DescriptionFrom Trip Setpoints Trip Tagnames When TS3000 (TRICON) is powered down -- External trip from ESDESDFalse7A50-X-6.01T Fail safe trip TS3000 (TRICON) False7A50-FSTRP EOST tripTS3000 (TRICON) 11096 RPM7A50-OSTRP Governor valve 2 coil fail trip TS3000 (TRICON) False7A50-V1TRP Extraction valve 2 coil fail trip TS3000 (TRICON) False7A50-V2TRP All speed pickups fail trip TS3000 (TRICON) False7A50-SPDFAILTRP Table 5-5-1-1: Trip Table A first out block will record the trip that caused the TS3000 (TRICON) Shutdown. An internal trip flag will trigger the first out capture. First out flags will be reset when sequencing enters Mode 1. Data will be generated in the TS3000 (TRICON) and will be captured/ logged in the HMI/ DCS/ SOE.Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:39of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 5.5.2ALARMS An alarm is a visual indication of an abnormal event or process condition which requires attention and/or corrective action from the operator. Alarms generated within the TS3000 (TRICON) will be recorded and captured/ logged in the HMI/ DCS/ SOE. Please refer to Appendix B for Interface List. The valve position feedback will be continuously monitored and a deviation alarm will be generated if the difference between the valve output and the valve position feed back signal is higher than or equal 5% for 2 seconds. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:40of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 67A50-K01/7A50-K01-TS01 CONTROL MODULE DESCRIPTION 6.1CONTROL MODULE ASSIGNMENT The control function is organized into Modules, with each Module performing specific tasks. Figure 6-1-1 Control Modules SP5SpeedPIDSP1SpeedInputMedianSelectSP3TargetSpeedSetpointSP4SpeedSetpointRampSP2Process/SurgeDecouplingSpeedBSpeedASpeedCOperatingModeSpeedRaise/LowerSC1SurgeControllerGovernorValveSV-5001AFsPsPdTsTdProcessOverrideMarginSpeedSetpointTargetSpeedActualSpeedSetpointActualSpeedSpeedControllerOutputExtractionValveSV-5002BTrackFlagTrackSignalPC1ExtractionPIDPIC-6003Min.SelectMPSteamPressurePT-5003AMPSteamPressurePT-5003BMasterSetpointfromDCS/HMIY1=X1-50kPaY2=X1+50kPaY3=X1+100kPaX1CALCX4%=X2/RangeRange=330T/HMPSteamFlowFT-5002PC3ExtractionBypassPIDPIC-5003BX3X4Y=X3+X4PC4MPSteamVentValvePIDPIC-5003AY1PVBypassValvePV-5003BMPSteamVentValvePV-5003A1ST&2NDStagesAnti-surgeValveFXV-5012Y3PVSuctionPressurePT-5011SetpointfromDCS/HMIPC2SuctionPressurePIDPIC-5011X2ToRefrigerationCompressorExtractionPressurePIDY2PVExtractionControllerOutputX6.01SP6TwoValveAlgorithmProject Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:41of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) The following is a list of control modules used in this application. They are presented here in execution order. ModuleFunction SP1Speed Input Median Select SP2Process / Surge Decoupling SP3Target Speed Setpoint Generator SP4Speed Setpoint RampSP5Speed PID SP6Two Valve Algorithm PC1Extraction Pressure PID PC2Compressor Suction Pressure PID PC3Extraction Bypass PID PC4MP Steam Vent PID SC1Anti-Surge Control Table 6-1-1: Control Modules Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:42of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.27A50-K01-TS01 STEAM TURBINE CONTROL MODULES 6.2.1SP1 - SPEED INPUT MEDIAN SELECT This module calculates a combined speed measurement based on the values of the three speed pickup inputs. It will continually output a selected speed value based upon the number of good speed pickups. The function returns an output value of zero when all enabled speed pickups fail or all are disabled. Low speed failure testing can be enabled when certain pre-determined condition are met. Logic Pickup failure logic is enabled when the turbine reaches Mode 2 and the speed is above 250 RPM.Once speed pickup failure detection is enabled, a pickup will fail if it drops below 200 RPM.The median value of the three speed pickup is used for Speed Control. If one pickup fails, the higher of the two remaining good speed pickup will be used. If two pickups fail, the remaining pickup will be used. The turbine will be tripped when three pickups fail. The turbine will be tripped when actual speed indicates a speed above the over speed trip setpoint. Peak Speed and Trip Speed will be recorded. These variables will be reset upon entering Mode 2 from Mode 1. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:43of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.2.2SP2 PROCESS / SURGE DECOUPLING This module controls the Suction pressure through the compressor, and is achieved by adjusting the speed of the compressors and/or the opening of the Anti-Surge valve. Decoupling is enabled when the Performance Controller is enabled. If the surge controller is in fully manual only the speed will be adjusted by the decoupling block. If Process Speed Control is disabled and Local mode, Target Speed can be raised/ lowered via the Speed Raise/ Lower Pushbutton from HMI. If Process Speed Controller is disabled and Remote mode, Target Speed can be raised/ lowered via the Speed Raise/ Lower Pushbutton from DCS. The Target Speed setpoint will raise or lower at normal ramp rate (500 RPM/MIN). If Performance Control is enabled and remote, Target Speed is set by the Decoupling Block to Compressor 1ST Stage Suction Pressure Controller (0-100% Signal).. Actual Speed Setpoint is ramped towards the Target at normal ramp rate (500 RPM/MIN). Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:44of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.2.2.1DYNAMIC BREAKPOINT The point at which Suction pressure control switches from controlling speed to opening the Anti-Surge Valve s called the Dynamic Breakpoint. This point is dynamic because it varies depending on the operating conditions of the compressor. If the controller output increases above the Breakpoint then the turbine speed is increased, if the controller output decreases below Breakpoint then the Anti-Surge Valve opens and speed is maintained at the Breakpoint amount. Logic The Dynamic Breakpoint is prevented from decreasing more than 1.0% (Breakpoint Hover) less than the controller output. The Dynamic Breakpoint is limited from declining quickly as a result of a rapid decrease in Suction pressure controller output. The Breakpoint will ramp to the left fast if the surge margin is greater than 10% above the surge control line and slowly when the surge margin is less than 10% and greater than Maximum Zone line. If the Suction pressure controller output decreases below the Breakpoint, the Anti-Surge Valve will open. The Breakpoint will continue to ramp down until either the surge margin is within 5% (Maximum Zone line) of the control line or until 50 % (minimum governor), or until the Suction pressure controller is satisfied, whichever comes first. If the surge margin is within 2% of the control line, the Dynamic Breakpoint is increased. If the surge margin is between 2% and 5% greater than the control line then no change is made to the Dynamic Breakpoint. The Breakpoint is limited from going below 50% (minimum governor). Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:45of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.2.2.2GAIN ADJUSTMENT An adjustment is available to balance the action of the speed setpoint and Anti-Surge valve. Typically a gain of 1 is used which represents that 1% of Anti-Surge Valve change is equivalent to 1% of speed setpoint change. A gain higher than 1 would be used in applications with large Anti-Surge Valves that have a bigger impact than changing the speed setpoint. 6.2.2.3PROCESS OVERRIDE If Decoupling is disabled, Process Override is set to 0%. If Decoupling is enabled, Process Override opens the Anti-Surge Valve when operating point is close to the Control Line or on rapid decreases of process controller output. Logic As the Suction pressure controller output increases from Dynamic Breakpoint - 50 to the Dynamic Breakpoint the Anti-Surge Valve closes from 100 to 0%.The Process Override is high-selected with the Anti-Surge controller to open the Anti-Surge valve.If surge control is not selected, Process Override is set equal to the Anti-Surge Valve output. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:46of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.2.2.4DECOUPLING SPEED SETPOINT If Decoupling is disabled, Target Speed is set equal to the speed setpoint from DCS or HMI depending on whether it is in LOCAL or REMOTE mode. If Decoupling is enabled, Target Speed is set equal to the Decoupling Speed Setpoint. Logic The speed setpoint is limited from going below the Dynamic Breakpoint. The speed setpoint is scaled to suction pressure controller output 50% - 100% to Minimum Governor Speed - Maximum Governor Speed. Since the Dynamic Breakpoint is clamped from going below 50%, it is not possible to calculate a negative speed setpoint. If Performance Control is not enabled, Speed Target is set equal to the Speed Setpoint Generator output (Module SP3). If only Performance Control is enabled, Speed Target is set directly by the Process Pressure controller. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:47of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.2.2.5PROCESS CONTROLLER TRACKING There are instances where the Process controller output to the Decoupling block must be back calculated to avoid a bump or lag in control response. When these instances occur, the Track Flag (TR_flag) will turn on and remain on until the Process controller tracks to within the DEMAND_TOL of the back-calculated demand. Logic Track if: The Surge_Enb flag is turned either On or Off. The Proc_Enb flag is turned either On or Off The Demand is less than the equivalent amount minus DEMAND_DB at which the surge valve is fully open (surge valve is not opening enough). The Demand is greater than the equivalent amount plus DEMAND_DB at which the process setpoint is at 100% (speed setpoint is not increasing enough). The Demand is on the left side of the dynamic breakpoint and exceeds the equivalent amount plus DEMAND_DB at which SRG_VLG is less than the SRGVLV_TRK (surge valve is not closing enough). The Demand is on the right side of the dynamic breakpoint and is less than the equivalent amount minus DEMAND_DB at which PROCESS is less than PROCESS_TRK or the Demand is less than the Dynamic Breakpoint Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:48of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.2.3SP3 TARGET SPEED SETPOINT Based on the current turbine Mode and various operator inputs, this module produces a target speed setpoint.Since its value changes instantaneously, a ramp function (Module SP4) is used to smooth out the output prior to use by the PID. Logic Based on the current turbine Mode and various Operator inputs, this module determines the target speed setpoint.Once the turbine has entered Mode 4 (Run), the Operator may select Speed or Performance Control mode. This setpoint will default to min governor.Target Speed Setpoint tracking in Mode 4 only. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:49of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.2.4SP4 SPEED SETPOINT RAMP Ramp blocks are used to move any of the various actual setpoints to their associated target setpoints at a steady, smooth rate.It is designed for speed setpoint ramping with critical speed band evasion, and speed target setpoint clamping within operating limits. This prevents step changes in the setpoints that could cause instability in the control loop. Logic In Modes 0 or 1, the Target Speed Setpoint and the Actual Speed Setpoint is set to 0 RPM. In all other mode, the Actual Speed Setpoint is ramped towards the Target Speed at the normal ramp rate (500 RPM/MIN). In the critical speed band, the Actual Speed Setpoint is ramped towards the Target Speed at the fast ramp rate (2000 RPM/MIN). During normal operation (Mode 4, Run), the Speed Setpoint Ramp is prevented from driving the speed greater than Maximum Governor. During normal operation (Mode 4, Run), the Speed Setpoint Ramp is prevented from driving the speed less than Minimum Governor. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:50of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.2.5SP5 SPEED PID This is a standard PID controller. It is always enabled. The direction of controller action is set to reverse action, which means that if the measurement increases, the PID output decreases. Logic This is a standard PID control algorithm. It will be configured for the following: Reverse Action Gain on change of error Setpoint tracking is enabled.Output limits are from 0 to 100%. Whenever the Mode is < 4, the start-up Proportional Band and Integral values are selected Whenever the Mode is 4, the normal Proportional Band and Integral values are selected. During normal operation (Mode 4, Run) the Speed PID Controllers setpoint is prevented from going above Maximum Governor. During normal operation (Mode 4, Run), the Speed PID Controllers setpoint is prevented from going below Minimum Governor. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:51of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.2.6SP6 TWO VALVE ALGORITHM This algorithm is used to control the turbine Speed and Turbine Extraction Flow. Logic The Two-Valve Algorithm uses both the Speed PID Output and Extraction Pressure PID Output to determine the Governor Valve (V1) and Extraction Valve (V2) positions.To increase speed, both valves will open. To decrease speed, both valves will close. To increase extraction steam pressure, V1 opens and V2 closes.To decrease extraction steam pressure, V1 closes and V2 open.During the start-up, V2 will be ramped to fully open and will stay in this way until the Run Mode is entered and the Extraction Steam Pressure Control is enabled. Priority will be given to the speed in the case that the extraction steam pressure and speed cannot be both maintained. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:52of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.3.1PC1 EXTRACTION PRESSURE PID This is a standard PID controller. It is always enabled. The direction of controller action is set to reverse action, which means that if the measurement increases, the PID output decreases. Logic This is a standard PID control algorithm. It will be configured for the following: Reverse Action Gain on change of error Setpoint tracking is enabled.Output limits are from 0 to 100%. During normal operation (Mode 4, Run) the Extraction PID Controllers setpoint is prevented from going above Maximum value of the extraction pressure. During normal operation (Mode 4, Run), the Extraction PID Controllers setpoint is prevented from going below Minimum value of extraction pressure. If both pressure transmitters (7A50-PT-5003A, 7A50-PT-5003B) fail, the PID will switch to Manual mode. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:53of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.3.2PC2 1ST STAGE SUCTION PRESSURE PID This is a standard PID controller. It is always enabled. The direction of controller action is set to direct action, which means that if the measurement increases, the PID output increases. Logic This is a standard PID control algorithm. It will be configured for the following: Direct Action Gain on change of error Setpoint tracking is enabled.Output limits are from 0 to 100%. During normal operation (Mode 4, Run) the suction pressure PID Controllers setpoint is prevented from going above maximum value of the Suction pressure. During normal operation (Mode 4, Run), the suction pressure PID Controllers setpoint is prevented from going below minimum value of suction pressure. If the suction pressure transmitter (7A50-PT-5011) fails, the PID will switch to Manual mode. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:54of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.3.3PC3 EXTRACTION BYPASS PID This is a standard PID controller. It is always enabled. The direction of controller action is set to reverse action, which means that if the measurement increases, the PID output decreases. Logic This is a standard PID control algorithm. It will be configured for the following: Reverse ActionGain on change of error Setpoint tracking is enabledOutput limits are from 0 to 100% During normal operation (Mode 4, Run) the Extraction Bypass PID Controllers setpoint is prevented from going above maximum Value of Extraction Pressure - 0.05 MPaG During normal operation (Mode 4, Run), the Extraction Bypass PID Controllers setpoint is prevented from going below minimum Value of Extraction Pressure - 0.05 MPaG If both pressure transmitters (7A50-PT-5003A, 7A50-PT-5003B) fail, the PID will switch to Manual mode 2 seconds after the signal 7A50-X-6.01T becomes active, the percent of extraction flow kicks in as a one-scan pulse and be added to the PID output Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:55of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.2.7PC4 MP STEAM VENT PID This is a standard PID controller. It is always enabled. The direction of controller action is set to direct action, which means that if the measurement increases, the PID output decreases. Logic This is a standard PID control algorithm. It will be configured for the following: Direct Action Gain on change of error Setpoint tracking is enabledOutput limits are from 0 to 100% During normal operation (Mode 4, Run) the MP Steam Vent PID Controllers setpoint is prevented from going above maximum value of Extraction Pressure + 0.1 MPaG During normal operation (Mode 4, Run), the MP Steam Vent PID Controllers setpoint is prevented from going below minimum value of Extraction Pressure + 0.1 MPaG If both pressure transmitters (7A50-PT-5003A, 7A50-PT-5003B) fail, the PID will switch to Manual mode Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:56of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.3SC1 ANTI-SURGE CONTROLLER 6.3.4SC1 ANTI-SURGE CONTROLLER The Anti-Surge control scheme discussed in this section is applicable to all four stages of the compressor. The Anti-Surge controller consists of a standard surge control package (Pd/Ps vs. corrected element dp (hc) algorithm). During Start-up, the operator would not be able to set a desired Anti-Surge Valve position. The Anti-Surge Valve is at full open position (100%). When Operating Mode is Run Mode (Mode 4), the operator would be able to select 2 modes of Control: Auto: Auto does not allow the operator to set a desired Anti-Surge Valve position. It is controlled by the surge controller or a process control loop. Partial Authority Manual: Partial Authority allows the operator to set a desired Anti-Surge Valve position. The operator can open or close the Anti-Surge Valve; however the surge controller will override any operator-entered valve position, based on surge control. NOTE: Throughout the surge control descriptions, 0.1013 MPa is added to each gauge pressure to convert the pressure to absolute.Also, 273.15 is added to each temperature to convert the temperature to absolute.Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:57of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.3.5FLOW COMPENSATION The compensation on flow measurements is done with pressure and temperature readings from downstream of the flow element. The compensated flow is calculated from the following: 15 . 273 _15 . 273 _*_1013 . 0 _100max _++ + =fo Tfob Tfob Pfo P hMFLOW MFLOW where: VariableDescription hFlow Element Measurement 0-100% MFLOWCompressor Compensated Flow MFLOW_maxMax Flow (Flow Element) P_foCompressor Pressure (Flow Element Side) T_foCompressor Temperature (Flow Element Side) P_fobFlow Element Design Pressure T_fobFlow Element Design Temperature Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:58of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.3.6OPERATING POINT This module calculates the compressor operating point when the compensated flow is available. It is a calculation of an equivalent suction flow based on a flow meter located in the suction. The compressor operating point is calculated from the following: 10015 . 27315 . 2731013 . 0 max _2+++ =TsbTsPsPsbMFLOWMFLOWHc where: VariableDescription HcCompressor Operating Point MFLOWCompressor Compensated Flow MFLOW_maxMax Flow(Compressor) PsCompressor Suction Pressure TsCompressor Suction Temperature PsbCompressor Base Pressure TsbCompressor Base Temperature Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:59of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.3.7PRESSURE RATIO The pressure ratio is calculated from the following: 1013 . 01013 . 0++=PsPdPRAT Where: VariableDescription PRATCompressor Pressure Ratio PsCompressor Suction Pressure PdCompressor Discharge Pressure Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:60of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.3.8ANTI-SURGE CONTROLLER CONFIGURATION Logic The actual operating margin is the distance from the Operating Point to the Surge Point. Automatic readjustments of the surge safety margin (Configurable: 2% by default) are made if the margin decreases less than -1%. The recalibration feature is not enabled if full manual authority has been selected. Automatic adjustment of the control line can be reset from HMI. There is one Surge Counter and it will not be resetable. The control line is generated by adding a base safety margin to the surge line. This base safety margin can be adjusted (engineer level). Default is 10%. Setpoint Hover function opens the Anti-Surge Valve on a sudden large movement towards surge. The Setpoint hover forces the setpoint of the Surge PID to track the Operating Margin minus a Hover Margin to a maximum of 20%. This allows the controller to track an increase in Operating Point instantly while allowing a configurable rate at which the Operating Point can approach the surge line. The Surge Override Function forces the Anti-Surge Valve to open independently of controller tuning when the operating point is some percentage (configurable) to the left of the hover line. Default is 70%. Adjustable valve slew rates are provided. Maximum opening and closing ramp rates (%/sec) are configurable. A dead band is also configurable (2% by default) which is the amount the valve is allowed to move in the either direction before the slew rates go into affect. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:61of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.3.9ANTI-SURGE VALVE AND TRACKING LOGIC In the Auto Authority Mode, the output signal to the Anti-Surge Valve is the greater of the following signals: Surge PID Output Surge Override Output Process Override Output In the Partial Manual Authority Mode, the output signal to the Anti-Surge Valve is the greater of the following signals: Surge PID Output Surge Override Output Process Override Output Manual Demand Signal In the Full Manual Authority Mode, the output signal to the Anti-Surge Valve is Manual Demand. If the Anti-surge Controller is not in Control, its Output is limited from decreasing 0.1 % less than the Anti-Surge Valve output. This is to prevent reset windup on the Anti-Surge controller. When in Auto, the manual valve demand position will track for a bumpless transfer. NOTE: Section 6.3 applies to all stages in of the Compressor. For details of application, please refer to Appendix D - Application Details Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:62of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 6.3.10TRANSMITTER FAIL-OVER STRATEGY Temperature transmitter is considered to have failed if its reading falls below 3.2 mA (655 counts) or rises above 21.6 mA (4423 counts). When the temperature transmitters (Suction or Discharge) fail, the algorithm reverts to a safe-value for the measurement (this value will be the base temperature of the flow element calculated at normal operating conditions) maintaining the entire surge algorithm features. Pressure transmitter is considered to have failed if its reading falls below 3.2 mA (655 counts) or rises above 21.6 mA (4423 counts). When the pressure transmitters (Suction or Discharge) fail, the control reverts to Minimum Uncompensated Flow Control. The base suction pressure from the compressor data sheet will be input to maintain the pressure ratio calculation. If the temperature/pressure transmitter is located at the flow element side and the temperature/pressure transmitter fail, the base temperature/pressure value from the flow element datasheet will be used. If the temperature/pressure transmitter is not located at the flow element side and the temperature/pressure transmitter fail, the base temperature/ pressure value from the compressor datasheet will be used. Flow transmitter is considered to have failed if its reading falls below 3.2 mA (655 counts) or rises above 21.6 mA (4423 counts) When the flow transmitter fails, the Anti-Surge controller reverts to Full Authority Manual Control, with the valve held in its last position and will give the alarm message to operator. Anti-surge Controller switches automatically from Full Manual to Partial Manual when the flow transmitter recovers from failure. All transmitters will remain failed unless they return to the acceptable range and remain in this range for a period of five minutes, after which the transmitter will be placed back into service. Project Name: Ma'aden Ammonia ProjectDoc. No.:SG60016-TC2-TMC-BODD-10001 Rev.:D03 Project Location : Ras Az Zawr City, KSAProject No.:SG60016 Document Description : Basis of Design DocumentContract No.:4500039280 Area/Unit/System Description 7A50-K01/K01-TS01Page:63of98 Customer Doc:- MD-502-7000-IN-BOD-1025-2011 INVENSYS PROCESS SYSTEMS (S) PTE LTD (File Name: SG60016-TC2-TMC-BODD-10001-RD03) 7DUAL COIL ACTUATOR CONFIGURATION A single high-current analog output supplies the signal for both coils of the dual coil actuator. The current is divided according to the impedance of the two coils. The power produced by the actuator coils is a function of the number of coils and the current through them. If only one coil is used, the current must double to maintain the same power. Because the controller output is a constant current, failure of one coil diverts all the current through the remaining coil, thus maintaining the correct actuator output. For example: If the controller output is 160 mA and the coil impedance is equal, the controller output is split evenly, supplying 80 mA to each coil. If one coil fails, all of the controller output current (