Transcription of Control Loop Performance Monitoring AT Ras Gas, Qatar
1 11 Control Loop Performance MonitoringAT Ras Gas, QatarMayan ShahApplications Engineer2 CONTENTS6 RasGas Overview6 Common Plant Performance Issues 6 CLPM Objectives6 KPIs for Control System6 Improvements6 Lessons Learnt6 Way Forward23 The RasGas Environment6 High growth of operational complexity and capacity6 Increasing product portfolio volumes and diversity6 LNG, Condensate, Flowing Gas, Helium, LPG's4 Components of Onshore FacilityInlet FacilitiesTreating/ DehydrationHeavy Hydrocarbon RemovalLiquefactionRefrigerationUtilitie sAcid Gas DisposalRefrigerant Preparation & Storage35 Common Plant Performance Issues Control View6 loops operating in manual or local6 Valve fully open or closed6 Different Performance under different conditions -loop robustness6 Instability at any operating point6 Excessive valve maintenance / poor valve response6 Poor set point response6 Frequent operator interventions6 Poor load rejection6 Unexplained oscillations6 OverviewObjectivesA.
2 Pre-requisite for APC ImplementationTo keep regulatory loops responsive and optimised so that advanced controllers can do their job of optimisation against Establish Benchmark AND KPIs TO:6 Define Baseline 6 Identify Poor Performers6 Maintain ImprovementsC. Help Optimize Regulatory Controls TO:6 Reduce Interactions / Disturbances6 Improve Robustness Over Controllable Range6 Maximize Benefits PRE-MPC Implementation at DCS LEVEL47 KPI s for Control System Performance6 Control Loop Availability % Time in Manual % Time output at limit % Time PV unavailable % Time PV at limit % noise in PV Mode changes/shift6 Control Loop Performance Integrated error IAE, ISE. IE Valve wear (travel and reversals) Oscillation% hysteresis& % stiction% time in oscillation% error vs operating point Cross-correlation 8 Control loops are Economic Assets.
3 Train-3 Study shows of Control loops were had controller output at had excessive valve involved high Before N/APV N/APV Comparison before and after tuning6726 Reversal - KPIV alve Reversal - %TValve Reversal - %E3448% Travel KPIV alve Travel - %TValve Travel -% -KPIO utput - %TOutput - % Error KPI Error - % Error - % Variability KPIV ariability - %TVariability - % to ThresholdAfter TuningBefore TuningKey Performance611 ImprovementsIDENTIFIED6 Normal Modes requirements6 Valve Travels and Reversals6 Variability12 LESSONS LEARNT6 Project Execution6 Training6 Project execution Team 6 Follow-up post-installation6 Technical6 LNG experience6 System Configuration issues713 Way forward6 Continuous Improvement of Control loops prior to APC implementation6 Run and analyze reports regularly (Monthly)Started developing Process Surveillance Monthly report to indicate6 Top 10 Biggest Payback loops6 KPIs6 Roll-Out, Training and System Access6 Continuous Improvement Procedure14 Thank you for your participation Questions ?
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