Mô phỏng công nghệ hóa học và dầu khí - Unit 8: Teg dehydration tower

Nhóm Mô phỏng Công nghệ Hoá học và Dầu khí Trường Đại học Bách khoa Hà Nội Dynamic Modeling using UniSim Design Unit 8 TEG Dehydration Tower Learning Objectives  Configure a Distillation Column in SS Mode  Prepare Distillation Column for Dynamic simulation  Model a typical TEG Dehydration Unit  Determine Water Dewpoint for a Gas  Research Tower Height to Dewpoint 2 Content  What is Dehydration Process  Steady State Model  Dynamic Model  Set up the PID Controller 3 Dehydration process Why use Dehydration? At the wellhead, reservoir fluids generally are saturated with water  The water in the gas can present some problems:  Formation of solid hydrates can plug valves, fittings, or pipes  The presence of water along with H2O or CO2 can cause corrosion problems  Water can condense in the pipeline causing erosion or corrosion problems 4 Dehydration process  What is Dehydration? Dehydration of natural gas: Removal of the water that is associated with natural gases in vapor form 5 Dehydration process 6 7 Dehydration process Adding the Column We will first build the column in steady state  Transition the whole model back to steady state, add and converge the column, then transition back to dynamics  Create a new model in steady state mode of the column only and use this as the starting point for dynamic simulation Advantage: Use the second method 8 Prepare the SSModel 1. Open case 07.CompE.usc. 2. Rename the exit Stream leaving PIPE-100 (Stream 5) to To TEG Contactor 3. Enter the Basis Environment (Ctrl + B) and add TEG (Triethylene Glycol) to the Component list. 4. Export the Fluid Package (*.fpk) 9 Add TEG in Component List–1 10 Export the Fluid Package 11 Add Stream 5. Create a New Case (Ctrl + N) and import file Export (Fluid Pkgs tab) in previous step 6. Creat a New Stream and copy the Temperature, Pressure, Flow and Composition from Stream To TEG Contactor (discussion) 7. Add Stream TEG from Regen (Mass Fraction) 12 6900 kPa Add a new Stream In this cell Enter Name TEG from Regen Temperature 25oC Pressure 7200 kPa Flow Rate 70 kgmole/h Component Mass Faction H2O 0.01 TEGlycol 0.99 13 Add a Valve 8. Add a Valve to stream TEG from Regen 9. Add an Absorber 14 6900 kPa Add an Absorber Connections Name TEG Contactor Number of Stages 3 Top Stage Inlet Stream TEG Recycle Bottom Stage Inlet Stream To TEG Contactor Ovhd Vapour Outlet Dry Gas Bottoms Liquid Outlet Btms Liq Parameters Top Pressure 6640 kPa Bottom Pressure 6640 kPa 15 Add an Absorber 16 Add an Absorber 10. Run the Absorber Column Converge the simulation 11. Save case as 08.TCSS 17 Sizing the Column TS 18 Tool → Utilities → Tray Sizing → Add Utility Sizing the Column TS 19 1 4 Sizing the Column TS 20 Sieve Design tab → Setup Sizing the Column TS 21 Performence → Results Sizing the Column TS 22 Design tab → Setup Sizing the Column TS 23 Performence → Results Export Pressure only used when P is specified, not calculated value Column Environment 24 Design tab → Pressure Column Environment 25 Rating tab → Sizing Column Environment  From the Tray Section property view, go to Specs page of the Dynamic tab  Select the Use Steady- State delta-P method box and click the All Stages button to calculate K valuaes 26 Column Environment 27 1 2 Dynamics tab → Specs Add a Separator In this Cell Enter Name TEG Sump Inlet Stream Btms Liq Vapour Outlet Stream Sump Vap Liquid Outlet Stream TEG to Regen 28 Add a Separator TEG Sum 29 Size the TEG Sump 30 1 Dynamics tab → Specs Add Valve to the Product Stream 31 Add Valve to the Product Stream 32 P out = 6200 kPa Add a Valve V-102 33 Add a Valve V-102 34 P out = 5500 kPa Sizing 3 Valve  Change the Valve Manufacturer to Universal Gas Sizing  Size the three Valve added to the simulation V-100, V-101, V-102  Add P-F specs to V-100, V-101, V-102  Save as case 08.TCSS1 35 Sizing Valve V-100 36 2 1 Sizing Valve V-101 37 2 1 Sizing Valve V-102 38 2 1 P-F Specs to 3 Valves 39 3 Adding the Column to Dyn Model 2 approaches could be used:  Simply copy the Steady State Column in to the Dynamic Model  Convert the Steady State Case to Dynamic Case, Run the Integrator and then Copy the Column in to the Dyn Mod If the model is lager and more complex than it should first be run in dynamics before importing into main model 40 Adding the Column to Dyn Model 1. Select all the Streams and Operations in the SS Column and Copy all objects 2. In the Dynamic Case 07.CompE, delete the pipe outlet stream 3. Paste the Column, attach the column feed stream, To TEG Contactor, to the pipe outlet 41 Adding the Column to Dyn Model 4. Remove P-F Specs from To TEG Contactor, then disconnect this Stream from the Column and connect it as the TEG Sump inlet 5. Remove P-F Specs from Sump Vap, Connect this stream to the Bottom Stage of Column 6. Run the Integrator for a few time Steps 42 Adding the Control System  Add a FC-TEG to the TEG Feed Stream PC-Dry Gas on Dry Gas Stream LC-Sump on TEG Sump  Start the Integrator  Save as Case 08.TCDyn.usc 43