Operator Training Simulator e Simulazione Dinamica. by Maria Regina Meloni 18 Novembre 2010

Transcription

1 Operator Training Simulator e Simulazione Dinamica by Maria Regina Meloni 18 Novembre 2010

2 Agenda Operations Environment Dynamic Simulation case study Operator Training Simulator Results and Conclusions

3 Operations Environment Safety Tight schedule External Factors (Market) Internal Factors Increased Complexity Long production runs Better design required

4 Operations Environment EPC Contractor :Quality is a given and shorter project schedules are a must. For Oil Companies it mandatory to maintain the production avoiding unplanned shut down. Oil Companies and EPC Contractors shall be able to explore and use market opportunities with short notice, without affecting quality, quantity and delivery schedules Market forces to be flawless and agile.

5 Dynamic Simulation Differences between dynamic and steady state simulation The main difference in dynamic and steady state modeling is the fact that dynamic modelling is datasheet driven while steady state modelling is driven by thermodynamics and specifications. TRANSIENT ANALISIS Software Platform UNISIM DYSIM HYSYS psig SP PV OP % open Flare B32PIC PV (left y-axis) B32PIC SP (left y-axis) B32PIC OP (right y-axis) Time 300

6 Dynamic Simulation MAIN TOPICS IN DYNAMIC SIMULATIONS a)volumes - Piping isometric data are needed to deduce the pipe-work volume and resistances. b) regulatory control needs to be included in a dynamic model - Compressor controls are always modelled c) Emergency Shutdown (ESD) logic is required in order to capture correctly the effects of a trip or of a sudden change in the operational conditions. d) Valve Cv, stroking time, characteristic curves, failure position, manufacturer are important for an engineering study. e) Compressor and driver data, f) Auxiliary systems are not modeled (compressor lube oil and seal systems, chemical injection, manual valves and drains, sample points etc). g) The thermodynamics and the component slate -

7 Dynamic Simulation Main benefit of the Dynamic Simulation is in the chance to test the equipment size and operating procedures (start up, emergency and normal shut down) for main gas compressor before real start up of the plants. Considering the tight commissioning schedules and the critically of these equipment the Dynamic Simulation allows a familiarization of compressor performance in the process environment with many months in advance; in time to identify problems (if any) and take corrective actions (if necessary). During the detail engineering phase, any possible options can be verified optimizing results.

8 Study overview Dynamic study LP/HP, 3 stages, electrical drivers, side streams Steam system (3 Aux. boilers, 4 HRSG, 5 GOSPs) Cases examined Flow disturbances (reduction, shutdown etc.) Trips, Start-up

9 First case study

10 First case study

11 First case study Dynamic Modeling Aspen Hysys Dynamics Steady state and plant design tool (as well) Steady state versus dynamic modeling Snapshot frozen in time versus change Differential mass and energy balances ( / t) Pressure drops across system instead of specs Process control

12 Experiences Inlet Isolation Valve Power Override Valve

13 Experiences JIC controller Normal: Power Override Start-up: Compressor loading (instead of inlet ZV) Detailed engineering phase Evaluated start-up alternatives Valve modifications Actions plan Reviewed valve sizes Verified equipment performance Verified plant controllability

14 second case study Aux Boiler Load Control PIC PIC Auxilliary Boiler A V3 V2 ATMOS Auxilliary Boiler B V1 PIT Auxilliary Boiler C USERS - 4 GOSP (Normal) - 1 GOSP (Future) - 2 GAS TRAINS HRSG1 HRSG2 EXCESS STEAM CONDENSERS HRSG3 MP STEAM TO LETDOWN HRSG4

15 % First case study % Boiler Load Time Five GOSPs, future operation All HRSG trip Both aux. boilers operating Consequences Shutdown of one GOSP is enough Boilers at 95% load Initial period of reduced MP steam flow

16 Experiences 128 KUC DSS psig vs time psig set Time B39_PIC0168A - PV B39_PIC0168B - PV B40_PIC PV B40_PIC PV Set 130 psig Set 116 psig Boilers Condenser set 120 psig

17 Conclusions Examined transients from test runs for (Compressors and Steam system) Trips Flow disturbances Start-up Suggested/Reviewed Controller modifications Plant procedures (start-up, )

18 Conclusions Benefits Availability to review during the Engineering Phase: Equipment size (also during abnormal conditions) Automation control philosophies Operating procedures POSSIBILITY TO TEST ANY OPTIONS OPTIMIZING THE RESULTS

19 Conclusions Benefits Plant reliability by early recognition of issues Optimize performance by early design changes Simulation follow-up: SMOOTHER START-UP Source of information Plant bottlenecks Process constraints Process familiarization

20 Operator Training Simulator

21 Operator Training Simulator

22 Operator Training Simulator

23 Operator Training Simulator

24 work in progress

25 Thanks for your attention!