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CHEMCAD Seminar Transport and Storage John Edwards, P&I Design Ltd January 2015

CHEMCAD Seminar Transport and Storage John Edwards, P&I Design Ltd January 2015. www.chemstations.com. HANDLING AND STORAGE SESSION OBJECTIVES. Review energy balance theory Understand derivation of resistance coefficients Develop user resistance coefficients

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CHEMCAD Seminar Transport and Storage John Edwards, P&I Design Ltd January 2015

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  1. CHEMCAD Seminar Transport and Storage John Edwards, P&I Design Ltd January 2015 www.chemstations.com

  2. HANDLING AND STORAGESESSION OBJECTIVES • Review energy balance theory • Understand derivation of resistance coefficients • Develop user resistance coefficients • Control valve characteristics & sizing parameters • Centrifugal pump sizing and rating • Design and rate piping distribution networks • Design and rate complex networks using Nodes Reference: Crane, “Flow of Fluids through Valves, Fittings and Pipes”, 410M Download: http://www.flowoffluids.com/ www.chemstations.com www.chemstations.net www.chemcad.co.uk

  3. HANDLING AND STORAGEFLUID FLOW BASIC THEORY Continuity Equation Bernoulli’s Equation Q volume flow a pipe area v velocity p pressure w density z height h line losses Combining for p1= p2 and z1 = z2 www.chemstations.com www.chemstations.net www.chemcad.co.uk

  4. HANDLING AND STORAGECIRCULAR PIPE FRICTION FACTORS Darcy Equation Form (CHEMCAD & CRANE 410M) L pipe length D pipe diameter f friction factor v velocity G 9.81 m/s2 Darcy > Fanning Friction Factor Fanning Friction Factor Equation Form www.chemstations.com www.chemstations.net www.chemcad.co.uk

  5. HANDLING AND STORAGEFRICTION FACTORS IN CHEMCAD Jain Equation Solves Darcy Friction Factor Matches Colebrook equation within 1.0% for 10-6 < ε / D < 10-2 and 5000 < Re < 108 Jain is CHEMCAD default method Churchill Solution Validity Applicable for all values of ε / D and Re www.chemstations.com www.chemstations.net www.chemcad.co.uk

  6. MOODY DIAGRAM (DARCY f) www.chemstations.com www.chemstations.net www.chemcad.co.uk

  7. HANDLING AND STORAGEFRICTION FACTOR CORRELATIONS Blasius more accurate for smooth pipe www.chemstations.com www.chemstations.net www.chemcad.co.uk

  8. CHEMCAD LOSSES IN PIPES AND FITTINGS ROUGHNESS COEFFICIENTS ε www.chemstations.com www.chemstations.net www.chemcad.co.uk

  9. LOSSES DUE TO FITTINGS Pressure Loss Coefficient Darcy Gradual Enlargement Kr Entry to pipe K = 0.5 Exit from pipe K = 1.0 Sudden enlargement Sudden contraction L pipe length D pipe diameter f friction factor v velocity G 9.81 m/s2 www.chemstations.com www.chemstations.net www.chemcad.co.uk

  10. CHEMCAD LOSSES IN PIPES AND FITTINGS DARBY 3K METHOD www.chemstations.com www.chemstations.net www.chemcad.co.uk

  11. CHEMCAD LOSSES IN PIPES AND FITTINGS L/D methods tend to under predict friction loss for larger D pipes. 3K method is most accurate for all Re and fitting sizes. STANDARD L/D VALVE AND FITTING LOSSES FROM CRANE 410 USER SPECIFIED OPTIONS INCLUDE L/D Manufacturers’ data Kr Derived from orifice calculation KS Sudden expansion or contraction coefficient (Crane K1) 3K Darby Method Enter appropriate K1 Ki KD www.chemstations.com www.chemstations.net www.chemcad.co.uk

  12. TEES STRAIGHT AND REDUCING Flow-thr Run Flow-thr Run UnitOp 2 UnitOp 1 UnitOp 3 Flow-out Branch Flow-in Branch “Tee Flow Thru Run” in pipe with largest flow rate L/D CHEMCAD=8.4 DARBY 3K=17 “Tee Flow Thru Run” CHEMCAD in both pipes Equates to DARBY 3K “Flow Out Branch” in branch pipe L/D CHEMCAD=58 DARBY 3K=51.2 “Flow In Branch” in branch pipe L/D CHEMCAD=43.2 DARBY 3K=51.2 Expansion Contractions always In smallest diameter pipe Unequal Tees install reducer in branch pipe www.chemstations.com www.chemstations.net www.chemcad.co.uk UnitOp 3 UnitOp 1 UnitOp 2

  13. CHEMCAD LOSSES IN PIPES AND FITTINGS www.chemstations.com www.chemstations.net www.chemcad.co.uk

  14. CRYOGENIC BATCH REACTOR OPTIMISATION PIPE DESIGN ECONOMIC VELOCITIES www.chemstations.com www.chemstations.net www.chemcad.co.uk

  15. ORIFICE PLATE TAPPINGS 2½D – 8D taps for flow restriction www.chemstations.com www.chemstations.net www.chemcad.co.uk

  16. EXPANSIONS AND CONTRACTIONS www.chemstations.com www.chemstations.net www.chemcad.co.uk

  17. CRYOGENIC BATCH REACTOR OPTIMISATION FLOW SCALERS WITH PRESSURE NODES Flows calculated from PIN and POUT Pipe (PIPE) Valve (VALV) Control Valve (CVAL) Pump (PUMP) Compressor (COMP) Expander (EXPN) www.chemstations.com www.chemstations.net www.chemcad.co.uk

  18. CRYOGENIC BATCH REACTOR OPTIMISATION PIPE NETWORKS - NODES(CALCULATORS) • All Network Flows and Pressures are interdependent • Junction pressures are equal and flows balance • Flows are calculated as a function of : • Inlet Pressure (Pin) & Outlet Pressure (Pout) • Flow Scalers calculate flow as a function of : • Inlet Pressure (Pin) & Outlet Pressure (Pout) • Nodes link all Flow Scaling UnitOps • Elevation of node entered > elevation change calculated www.chemstations.com www.chemstations.net www.chemcad.co.uk

  19. PUMP NPSH www.chemstations.com www.chemstations.net www.chemcad.co.uk

  20. PUMP NPSH www.chemstations.com www.chemstations.net www.chemcad.co.uk

  21. PIPE SYSTEM SIMPLE DESIGN Case 5.03 Piping Design Section 5-p155 NPSH Nett Positive Suction Head www.chemstations.com www.chemstations.net www.chemcad.co.uk

  22. PIPING SYSTEM DESIGN CASE 5.03 Case 5.03 Piping Design Section 5-p155 Objectives Pipe UnitOp Pump UnitOp Elevation change Pipe size(p121) Suction 5 ft/s Diam 4 in Discharge 10 ft/s Diam 3 in Simulation Basis Units English Component Glacial Acetic acid Thermo H – UNIFAC L - LH Feed Stream Q 220 gpm T 70°F P 20 psia Discharge P P > 20 psia T 140°F Pump Discharge T o be determined www.chemstations.com www.chemstations.net www.chemcad.co.uk

  23. PIPING SYSTEM DESIGN CASE 5.03 Case 5.03 Piping Design Section 5-p155 Objectives Pump selection 1.Manual method 2.Controller Pipe UnitOp Mode Single phase Sizing Rating Pipe Schedule Default Schedule 40 (p548) Size Determined by velocity Roughness Commercial steel Friction Churchill Elevation change Down – Negative Up - Positive Pump Discharge Initial trial 60 psia η 0.8 (Refinery p66) www.chemstations.com www.chemstations.net www.chemcad.co.uk

  24. PIPING DESIGN USING NODES CASE 5.04 Case 5.04 Pump Sizing and Pipe Branches Section 5-p158 www.chemstations.com www.chemstations.net www.chemcad.co.uk

  25. PIPING DESIGN USING NODES CASE 5.04 Case 5.04 Pump Sizing and Pipe Branches Section 5-p158 Piping design Deliver acetic acid 120 gpm 70 deg F at 20 psia to process Nodes Set inlet state Set elevations Set outlet state Flow scaler Here the pump Calculates Flow www.chemstations.com www.chemstations.net www.chemcad.co.uk

  26. PIPING DESIGN USING NODES CASE 5.04INLET AND OUTLET NODES Inlet Node Outlet Node Case 5.04 Pump Sizing and Pipe Branches Section 5-p158 www.chemstations.com www.chemstations.net www.chemcad.co.uk

  27. PIPING DESIGN USING NODES CASE 5.04PIPE FLOW AS FLOW SCALER Allows Flow to be set by UnitOp Case 5.04 Pump Sizing and Pipe Branches Section 5-p158 www.chemstations.com www.chemstations.net www.chemcad.co.uk

  28. PIPING DESIGN USING NODES CASE 5.04NODE BETWEEN FLOW SCALERS P set Variable or Fixed Boundaries for the pressure Flow set Fixed or Variable Case 5.04 Pump Sizing and Pipe Branches Section 5-p158 www.chemstations.com www.chemstations.net www.chemcad.co.uk

  29. PIPING DESIGN USING NODES CASE 5.04PUMP PERFORMANCE CURVE Case 5.04 Pump Sizing and Pipe Branches Section 5-p158 www.chemstations.com www.chemstations.net www.chemcad.co.uk

  30. PIPING DESIGN USING NODES CASE 5.04NODE BETWEEN FLOW SCALERS Case 5.04 Pump Sizing and Pipe Branches Section 5-p158 Excel Data Map Facility for Key Data Reporting www.chemstations.com www.chemstations.net www.chemcad.co.uk

  31. Simulation of more complex piping systems, as found in service distribution networks, to determine the pressure drops and the flows throughout the system. This case develops the design of a cooling water distribution system supplying three shell and tube heat exchangers. Piping Design and Rating CASE 5.05 COOLING WATER SYSTEM PIPING SYSTEM RATING Case 5.05 Cooling Water System Section 5-p163 Simulation Basis Units Common SI Component Water Thermo H – Ideal Vapor Pressure L - LH Feed Stream W 35000 kg/h T 15°c P 5 bar Heat Exchanger Duties 50 kW 100kW 150kW Heat Exchanger ∆P 0.5 bar Piping Design 3 m/s allow for upgrade to 75000 kg/h Restriction Orifice 0.5 bar pressure drop in spillback line Control Valve Sizing Flow based on 150kW POUT 3.5 bar Control valves are adjusted manually to achieve required duty www.chemstations.com www.chemstations.net www.chemcad.co.uk

  32. Piping Design and Rating PIPING SYSTEM RATING CASE 5.05 Case 5.05 Cooling Water System Section 5-p163 www.chemstations.com www.chemstations.net www.chemcad.co.uk

  33. Piping Design and Rating CASE D2.04 DYNAMIC TANKER OFFLOAD Case D2.04 Road Tanker Offload Section 2-p25 www.chemstations.com www.chemstations.net www.chemcad.co.uk

  34. Piping Design and Rating CASE 5.02 VALVE SIZING TWO PHASE FLOW Case 5.02 Control Valve Sizing and Flow Split Section 5-p152 Liquid NH3 225 psig -9 deg F Flow 226000 lb/h 50% split to two users 15 psig -1 deg F 0.2 psig -28 deg F Size control valves www.chemstations.com www.chemstations.net www.chemcad.co.uk

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