Mô phỏng công nghệ hóa học và dầu khí - Unit 6:Expanding the Model

Nhóm Mô phỏng Công nghệ Hoá học và Dầu khí Trường Đại học Bách khoa Hà Nội Dynamic Modeling using UniSim Design Unit 6 Expanding the Model Workshop  Hight Pressure Separator will be Expanded:  a Knockout Drum  3-phase low Pressure Separator  Control System:  Cadscade  On-off  Split Range 2 Objective  Add Unit Operations and Controllers in Dynmode  Make necessary P-V Specifications  Implement appropriate Control Strategies  Install a Relief Valve  Install an Air Cooler  Install a Pump 3 HP Separator  Open case 05.HL.usc in DynMod  Add valve: Knockout Valve  Inlet Stream: Hot Vap  Product Stream: Hot Vap Out  On Rating tab → Sizing page of the valve:  Set the Valve Manufacturers to Universal Gas Sizing  Sizing the valve: 70 kPa Pressure Drop 4 HP Separator  PF Specs:P Specs Hot Vap → Hot Vap Out  P of Hot Vap Out = 6340 kPa  Start Integrator a few minutes 5 2 3 1 HP Separator  PC-HP Sep: Output Target Object: Object: Knockout Valve Variable: Actuator Disired Mode: Auto  Set the appropriate  Action in PC-HP Sep  Set Point: 6480 kPa 6 1 2 Adding the Knockout Drum  Turn off Integrator  Adding Separator 7 In this cell Enter Connections Name Knockout Drum Inlet stream Hot Vap Out Vapour outlet stream KO Vap Liquid out stream KO Liq Parameters Volume 25 m3 Adding the Knockout Drum  P-F Specs of both new boundary streams:  P- Specs for KO Vap  F- Specs for KO Liq  Dynamic tab: check the content of vessel holdup based on the feed stream to the vessel is 50%.  Run Integrator a few minutes 8 Reverse Flow  P-F Theory: resistance device should be added tho both of thw Knockout Drum streams and P- Specs should be used (boundary streams) P-Specs on vapour product F-Specs on liquid product  Dynamics tab Specs page → Product Block Exit stream will either let flow out of the vessel or let flow into the vessel (reverse flow) Product Block: Defines the conditions if there is negative → reverse flow 9 Reverse Flow 10 Valve LP Separator Valve  Make sure the liquid level in the Knockout Drum not so low that there is vapour in the liquid product  Add valve following information: 11 In this cell. Enter Conections Name LP Separator Valve Inlet stream KO Liq Outlet stream To LP Sep Valve LP Separator Valve  Move P-F Specs to their proper locations  Pressure of stream To LP Sep the same as stream HP Liq1  Set the Valve Manufacturers to Universal Gas Sizing and size valve  Run Integrator a few seconds  Add a Level Controllers for Knockout Drum  Set Point: 50% 12 LP Separator 13 In this cell.. Enter Connections Name LP Separator Inlet stream 1 HP Liq 1 Inlet stream 2 To LP Sep Vapour outlet LP Vap Light liquid outlet LP Liq Heavy liquid outlet Waste Water Parameters Volume 127 m3 LP Separator 14 LP Separator 15 Boot Diameter: 1.5m Boot Height: 2.0m LP Separator 16 1 LP Separator  P-F Specs: P-Specs for stream LP Vap F-Specs for LP Liq and Waste  Start Integrator and run a few minutes  Check the Rating tab Nozzles page and Dynamic tab Holdup page to view:  The nozzles positions  The different phase level  Volumes 17 Valve to LP Vap Stream In this Cell Enter Name LP Pressure Valve Inlet Stream LP Vap Oulet Stream LP Vap1 Pressure of outlet stream 1380 kPa 18 PID-Pressure Controller In this cell Enter Connections Name PC-LP Sep Process Variable Source LP Vap – Pressure Outlet Target Object LP Vap Valve – Actuator Desired Position Parameters Action Direct Range PV minimum 1380 kPa Range PV maximum 3100 kPa Mode Auto (matic) SP 2690 kPa Kc 3.0 Ti 2.0 19 Valve to LP Liq Stream In this Cell Enter Name LP Level Valve Inlet Stream LP Liq Oulet Stream LP Liq1 Pressure of outlet stream 1380 kPa 20 PID-Level Controller In this cell Enter Connections Name LC-LP Sep Process Variable Source LP Separator – Liquid Percent Level Outlet Target Object LP Level Valve – Actuator Desired Position Parameters Action Direct Range PV minimum 0% Range PV maximum 100% Mode Auto (matic) SP 65% Kc 1.0 Ti 15.0 Td 21 Valve to Waster Water Stream In this Cell Enter Name LP Waster Valve Inlet Stream LP Waster Water Oulet Stream LP Waster Water1 Pressure of outlet stream 1380 kPa 22  Add Digital Point Controller for On-Off Controller Water Level On/Off Controller In this cell.. Enter.. Connections Name Waste Water On/Off Process Variable Source LP Separator – Phase Level – Phase Level_3 Outlet Target Object LP Waste Valve – Digital Actuator Desired Position 23 Water Level On/Off Controller 24 Parameter Mode Auto (matic) Cold Init OP On Radion Button Setting Latch Threshold 0.4 m Higher Dead Band 1.4 m Lower Dead Band 0 m OP is On when PV >= Threshold Face Plate Configurations Minimum PV 0 m Maximum PV 2.5 m Water Level On/Off Controller  Show Face Plate  Run Integrator a few minutes and observe 25 Adding Strip Charts  Create Strip Chart to monitor primary variable in the flowsheet  Start Integrator and allow the model stabilize  Once the model has reached steady state, create a disturbance to test model  Save as 06.Mods.usc 26 Adding Strip Charts  All Variables 27 2 1 Exercises-Cascade Controller  Adding Cascade Controller  Flow more sensitive for controller  For slow acting control loops (e.g. level controllers) it is desirable to place a fast acting controller (e.g. flow controllers) into the loop  Place FC on streams:  HP Liq stream  LP Liq stream  KO Liq stream with Kc = 0.1 and Ti = 0.2 28 Cascade Controller In this cell Enter Connections Name FC-HP Liq Process Variable Source HP Liq – Mass Flow Outlet Target Object VLV-100 – Actuator Desired Position Remote Setpoint LC-HP Sep Parameters Action Reverse SP Mode Remote Range PV minimum 0 kg/h Range PV maximum 5e+5 kg/h Mode Casc Kc 0.1 Ti 0.2 29 Cascade Controller 30 Cascade Controller 31 Exercises - ESD  Valve Emergency Shut Down (ESD): is system will open or close valves to make the plant safe  Dynamic tab Actuator page 32 Exercises - ESD  Trip Mode: position the valve moves to during an ESD trip (Open, Shut or Hold)  The behavior of the ESD Trip State checkbox depends on the setting on the Invert EDS State checkbox  In the event scheduler (Unit 9) the ESD Trip function of VLV-100 will be used to make safe a high liquid level situation in the HP Separator 33 Exercises - ESD  Dynamic tab Actuator page of VLV-100 select Trip Open  uncheck EDS Trip State  check Invert EDS State  Test the EDS Trip fuction of the valve: running integrator and cheking EDS Trip State  Return the valve to normal (non-EDS) 34 Test Valve Malfuntion 35 Test Valve Malfuntion  Malfunction page of VLV-100:  select the Actuator Failure ratio button  tick Use Malfuntion  Change Fail position to Fail open  Start integrator a few seconds  after press the unable Upset button  and observe the valve.  Press the Disable Upset button and observe the module return to normal 36 Adding Split Range Controller  Disconect the vapour stream from the LP separator to the control valve  Add a tee TEE-100 37 In this Cell Enter Inlet Stream LP Vap Outlet Stream 1 2 Adding a Tee Controller  Size the valve so that each is about 50% of the original valve size  Make the new boundary streams pressure at 1380 kPa  Use PID and Fanout to controllers Tee 38 Adding Split Range Controller  Add two valve  Sizing two Valve 50% 39 In this Cell Enter Enter Name LP Vap Valve A LP Vap Valve B Inlet Stream 1 2 Outlet Stream LP Vap 1 LP Vap 2 P outlet 1380 kPa 1380 kPa Adding Split Range Controller In this cell Enter Connections Name Split PC-LP Sep Process Variable Source LP Vap - Pressure Number of Output Target Objects 2 Outlet Target Object 1 LP Vap Valve A – Actuator Desired Position Outlet Target Object 2 LP Vap Valve B – Actuator Desired Position Parameters Action Direct Range PV minimum 1380 kPa Range PV maximum 3100 kPa 40 Adding Split Range Controller In this cell Enter Parameters (continue) Mode Auto (matic) SP 2690 kPa Kc 3.0 Ti 2.0 Td empty Split Range Setup Low Range High Range KO Vap Valve A 0 50 KO Vap Valve B 50 100 41 Adding Split Range Controller 42 Adding Split Range Controller 43 Adding a Tee Controller-FanOut In this cell.. OP1 OP2 Connection Object LP Vap Valve A LP Vap Valve B Variable Actuator current position Actuator current position Process Variabe Souces Object PIC-100 Variable OP Parameter Gain 1 2 Bias 0 -100 Low Limit 0 50 High Limit 50 100 Ramp time 60 60 44 Adding a Tee Controller-PID 45 Fanout-100 46 Fanout-100 47 Fanout-100 48 Adding a Pressure Relief Valve  Add a Relief Valve:  Outlet Stream: To Flare (Dynamic tab: Active P specs)  Inlet Stream: From LP  Third outlet Stream of the Tee: From LP  Rating tab Sizing page of Relief Valve: 25.81 mm2  Valve type: Linear  Design tab Parameter page:  Set Pressure of the relief valve: 2830 kPa  Full Open Pressure: 2890 kPa  Save as 06.RV.usc 49 Adding a Pressure Relief Valve 50 Adding a Pressure Relief Valve 51 Advanced Modeling Air Cooler Air Cooler:  Number of fans  Demanded speed of each fan  Design speed of each fan  Design air flow of each fan 52 Advanced Modeling Air Cooler  Delete Cooler E-100 & Add an Air Cooler  Design tab → Connection page:  Stream Inlet: HP Vap  Stream Outlet: Hot Vap  Energy Stream: Design tab → qE-100  Design tab → Parameter page:  Overall UA = 1.0e7kJ/C-h  Configuration: four tube rows, four pass  Air Intake Temperature: 20oC 53 Advanced Modeling Air Cooler 54 2 1 3 Advanced Modeling Air Cooler 55 2 1 3 Advanced Modeling Air Cooler  Rating tab → Sizing page: 56 In this cell Enter.. Parameters Tubes Wall Mass 0 kg Number of Fans 2 For each fan Demanded speed 360 rpm Max Acceleration per sec 10 rpm Design Speed 360 rpm Design Air Flow 1e6 ACT_m3/h Fan is ON ON Advanced Modeling Air Cooler 57 2 1 3 Advanced Modeling Air Cooler  Dynamic tab → Specs page:  Overall Delta P = 70 kPa  Press Caculated K button  Then uncheck Overall Delta P  And check Overall K value  Fluid Volume = 15 m3 58 Advanced Modeling Air Cooler 59 2 1 3 Temperature Controller  PID name TC-Hot Vap  Connection tab of TC-Hot Vap: Ouput Target Obj is Fan demanded Speed 1 60 Temperature Controller 61 Temperature Controller  Range of the Control OP Port: 0 - 600 rpm  Parameter tab: Mode Auto(matic)  Start Integrator and observe 62 Pump Some of the features of the dynamic pump:  Dynamic modelling of friction loss and inertia  Shut down and startup behavior modelling  Multiple head and efficiency curves  Ability to add an electric motor  Linking capabilities with other rotational equipment operating at the same speed with one total curves 63 Pump  Disconnect stream LP Liq from valve LP Level Valve  Add Pump P-100  Connect the pump inlet: stream LP Liq the pump outlet: valve LP Level Valve  Duty of pump: Q 64 Pump 65 Pump 66 1 Pump  Complete Generate Curves Option 67 3 2 1 Pump  Dynamic tab → Specs page:  Uncheck efficiency and pressure rise  And check use characteristic and speed (Important)  Speed Value = 3600 rpm  Change the boundary pressure of stream LP Liq1 to 3500 kPa  Start Integrator and observe. 68 Pump 69 Pump 70 3500 kPa Pump 71 Rating tab → Curves page → Plot Curves button Heat Exchange 1. Add Cooling Water stream 72 Parameter Value Name Cooling Water In Temperature 25oC Pressure 500 kPa Mass Flow 2e5 kg/h Composition 100% Water Pressure – Flow Specs Active both P and F Specs Heat Exchange 2. Add Heat Exchange: 3. Dynamic tab → Model page: Overall UA = 2.0e6 kJ/C-h 73 Tube in Coolling Water in Tube out Cooling Water out Shell in LP Liq1 Shell out Cold LP Liq Heat Exchange 74 2e6 kJ/C-h Heat Exchange 4. Dynamic tab → Specs page: Delta P = 50 kPa for both sides of HE 5. Press Calculate K’s  Uncheck Delta P  Check K for both sides of HE 6. Boundary stream Cold LP Liq: P Specs P = 3450 kPa 7. Run Integrator 75 Heat Exchange 8. Cooling Water In: Disable F spec Cooling Water Out: Enable P spec 9. Insert a Valve between the Coolling Water In stream and the Exchanger  Size it for a 100 kPa pressure drop  Name valve is CW FCV 76 Heat Exchange  Add the Temperature Controller 77 In this cell Enter Connection Name TC-E-100 Process Variable Source Cold LP Liq – Temperature Outlet Target Object CW FCV – Actuator Desired Position Parameter Action Direct Range PV minimum 25 oC Range PV maximum 75 oC Mode Auto (matic) SP 40 oC Kc 1 Ti 2 min Heat Exchange 78 Heat Exchange  Run integrator and obeserve.  Save case: 06.AC Pump HEX.usc 79 HEX Modeling in Dynamic  Dynamic tab → Model page: HEX hase been modeled using Basic Model  Basic Model: UA value is entered by user  Detailed Model: UA value is caculated based on the specified exchanger entered geometry  In reality: UA value changes as flows through HEX change → account for this Unisim Design allows UA value to be scaled according to the shell and tube side flows 80 HEX Modeling in Dynamic 81 HEX Modeling in Dynamic UAused = UAspecified x F F = 2𝑓1𝑓2 𝑓1+𝑓2 𝑓1 = 𝑆ℎ𝑒𝑙𝑙 𝑠𝑖𝑑𝑒 𝑀𝑎𝑠𝑠 𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑒 𝑆ℎ𝑒𝑙𝑙 𝑠𝑖𝑑𝑒 𝑅𝑒𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑒 0.8 𝑓2= 𝑇𝑢𝑏𝑒 𝑠𝑖𝑑𝑒 𝑀𝑎𝑠𝑠 𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑒 𝑇𝑢𝑏𝑒 𝑠𝑖𝑑𝑒 𝑅𝑒𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑒 0.8 82