[948] | 1 | #*------------------------------------------------------------------- |
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| 2 | * EMSO Model Library (EML) Copyright (C) 2004 - 2007 ALSOC. |
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| 3 | * |
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| 4 | * This LIBRARY is free software; you can distribute it and/or modify |
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| 5 | * it under the therms of the ALSOC FREE LICENSE as available at |
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| 6 | * http://www.enq.ufrgs.br/alsoc. |
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| 7 | * |
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| 8 | * EMSO Copyright (C) 2004 - 2007 ALSOC, original code |
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| 9 | * from http://www.rps.eng.br Copyright (C) 2002-2004. |
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| 10 | * All rights reserved. |
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| 11 | * |
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| 12 | * EMSO is distributed under the therms of the ALSOC LICENSE as |
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| 13 | * available at http://www.enq.ufrgs.br/alsoc. |
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| 14 | * |
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| 15 | *---------------------------------------------------------------------- |
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| 16 | * Author: Paula B. Staudt |
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| 17 | * $Id: tray.mso 522 2008-05-21 23:21:12Z arge $ |
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| 18 | *--------------------------------------------------------------------*# |
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| 19 | |
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| 20 | using "streams"; |
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| 21 | |
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| 22 | Model tray |
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| 23 | |
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| 24 | ATTRIBUTES |
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| 25 | Pallete = false; |
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| 26 | Icon = "icon/Tray"; |
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| 27 | Brief = "Complete model of a column tray."; |
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| 28 | Info = |
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| 29 | "== Assumptions == |
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| 30 | * both phases (liquid and vapour) exists all the time; |
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| 31 | * thermodymanic equilibrium with Murphree plate efficiency; |
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| 32 | * no entrainment of liquid or vapour phase; |
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| 33 | * no weeping; |
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| 34 | * the dymanics in the downcomer are neglected. |
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| 35 | |
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| 36 | == Options == |
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| 37 | You can choose the equation for the liquid outlet flow and the vapour |
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| 38 | inlet flow calculation through the VapourFlowModel and LiquidFlowModel |
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| 39 | switchers. |
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| 40 | |
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| 41 | == References == |
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| 42 | * ELGUE, S.; PRAT, L.; CABASSUD, M.; LANN, J. L.; CéZERAC, J. Dynamic models for start-up operations of batch distillation columns with experimental validation. Computers and Chemical Engineering, v. 28, p. 2735-2747, 2004. |
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| 43 | * FEEHERY, W. F. Dynamic Optimization with Path Constraints. Tese (Doutorado) - Massachusetts Institute of Technology, June 1998. |
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| 44 | * KLINGBERG, A. Modeling and Optimization of Batch Distillation. Dissertação (Mestrado) - Department of Automatic Control, Lund Institute of Technology, Lund, Sweden, fev. 2000. |
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| 45 | * OLSEN, I.; ENDRESTOL, G. O.; SIRA, T. A rigorous and efficient distillation column model for engineering and training simulators. Computers and Chemical Engineering,v. 21, n. Suppl, p. S193-S198, 1997. |
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| 46 | * REEPMEYER, F.; REPKE, J.-U.; WOZNY, G. Analysis of the start-up process for reactive distillation. Chemical Engineering Technology, v. 26, p. 81-86, 2003. |
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| 47 | * ROFFEL, B.; BETLEM, B.; RUIJTER, J. de. First principles dynamic modeling and multivariable control of a cryogenic distillation column process. Computers and Chemical Engineering, v. 24, p. 111-123, 2000. |
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| 48 | * WANG, L.; LI, P.; WOZNY, G.; WANG, S. A start-up model for simulation of batch distillation starting from a cold state. Computers and Chemical Engineering, v. 27, p.1485-1497, 2003. |
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| 49 | "; |
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| 50 | |
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| 51 | PARAMETERS |
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| 52 | outer PP as Plugin (Brief = "External Physical Properties", Type="PP"); |
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| 53 | outer NComp as Integer (Brief="Number of components"); |
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| 54 | |
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| 55 | Mw(NComp) as molweight (Brief="Component Mol Weight",Hidden=true); |
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| 56 | Gconst as acceleration (Brief="Gravity Acceleration",Default=9.81,Hidden=true); |
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| 57 | zero_flow as flow_mol (Brief = "Stream Flow closed",Default = 0, Hidden=true); |
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| 58 | low_flow as flow_mol (Brief = "Low stream Flow",Default = 1E-6, Hidden=true); |
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| 59 | Pi as constant (Brief="Pi Number",Default=3.14159265, Symbol = "\pi",Hidden=true); |
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| 60 | |
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| 61 | TrayDiameter_ as length (Brief="Tray Diameter",Default=1.600); |
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| 62 | TraySpacing_ as length (Brief="Tray Spacing",Default=0.600); |
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| 63 | Fraction_HoleArea_ as fraction (Brief="Fraction of the active area that is occupied by the holes with respect to the total tray area",Default=0.10); |
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| 64 | Fraction_DowncomerArea_ as fraction (Brief="Fraction of the downcomer area with respect to the total tray area",Default=0.20); |
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| 65 | WeirLength_ as length (Brief="Weir length", Default = 1); |
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| 66 | WeirHeight_ as length (Brief="Weir height", Default= 0.05); |
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| 67 | TrayLiquidPasses_ as positive (Brief="Number of liquid passes in the tray", Lower = 1,Default=1); |
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| 68 | HeatSupply_ as heat_rate (Brief="Rate of heat supply",Default = 0); |
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| 69 | AerationFraction_ as Real (Brief="Aeration fraction", Default = 1); |
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| 70 | DryPdropCoeff_ as Real (Brief="Dry pressure drop coefficient", Default= 0.60); |
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| 71 | MurphreeEff_ as Real (Brief="Murphree efficiency for All Trays",Lower=0.01,Upper=1); |
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| 72 | |
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| 73 | PlateArea_ as area (Brief="Plate area = Atray - Adowncomer",Protected=true); |
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| 74 | TrayVolume_ as volume (Brief="Total Volume of the tray",Protected=true); |
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| 75 | HolesArea_ as area (Brief="Total holes area",Protected=true); |
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| 76 | |
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| 77 | FeeheryCoeff as Real (Brief="Feeherys correlation coefficient", Unit='1/m^4', Default=1,Hidden=true); |
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| 78 | ElgueCoeff as Real (Brief="Elgues correlation coefficient", Unit='kg/m/mol^2', Default=1,Hidden=true); |
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| 79 | OlsenCoeff as Real (Brief="Olsens correlation coefficient", Default=1,Hidden=true); |
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| 80 | |
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| 81 | VapourFlow as Switcher (Brief="Flag for Vapour Flow condition",Valid = ["on", "off"], Default = "off",Hidden=true); |
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| 82 | LiquidFlow as Switcher (Brief="Flag for Liquid Flow condition",Valid = ["on", "off"], Default = "off",Hidden=true); |
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| 83 | |
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| 84 | VARIABLES |
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| 85 | |
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| 86 | Inlet as stream (Brief="Feed stream", Hidden=true, PosX=0, PosY=0.4932, Symbol="_{in}"); |
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| 87 | LiquidSideStream as liquid_stream (Brief="liquid Sidestream", Hidden=true, Symbol="_{outL}"); |
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| 88 | VapourSideStream as vapour_stream (Brief="vapour Sidestream", Hidden=true, Symbol="_{outV}"); |
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| 89 | |
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| 90 | in InletLiquid as stream (Brief="Inlet liquid stream", PosX=0.5195, PosY=0, Symbol="_{inL}"); |
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| 91 | in InletVapour as stream (Brief="Inlet vapour stream", PosX=0.4994, PosY=1, Symbol="_{inV}"); |
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| 92 | out OutletLiquid as liquid_stream (Brief="Outlet liquid stream", PosX=0.8277, PosY=1, Symbol="_{outL}"); |
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| 93 | out OutletVapour as vapour_stream (Brief="Outlet vapour stream", PosX=0.8043, PosY=0, Symbol="_{outV}"); |
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| 94 | |
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| 95 | LFlowModel as positive (Brief="Flag for Liquid Flow Model",Lower = 0, Default = 1 , Hidden=true); |
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| 96 | VFlowModel as positive (Brief="Flag for Vapour Flow Model",Lower = 0, Default = 1 , Hidden=true); |
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| 97 | |
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| 98 | M(NComp) as mol (Brief="Molar Holdup in the tray"); |
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| 99 | ML as mol (Brief="Molar liquid holdup"); |
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| 100 | MV as mol (Brief="Molar vapour holdup"); |
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| 101 | E as energy (Brief="Total Energy Holdup on tray"); |
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| 102 | vL as volume_mol (Brief="Liquid Molar Volume"); |
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| 103 | vV as volume_mol (Brief="Vapour Molar volume"); |
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| 104 | Level as length (Brief="Height of clear liquid on plate"); |
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| 105 | yideal(NComp) as fraction; |
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| 106 | rhoL as dens_mass (Brief="Mass Density of liquid phase"); |
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| 107 | rhoV as dens_mass (Brief="Mass Density of vapour phase"); |
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| 108 | |
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| 109 | SET |
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| 110 | |
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| 111 | Mw = PP.MolecularWeight(); |
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| 112 | zero_flow = 0 * 'kmol/h'; |
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| 113 | low_flow = 1E-6 * 'kmol/h'; |
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| 114 | |
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| 115 | PlateArea_ = 0.25*Pi*(TrayDiameter_^2)*(1-Fraction_DowncomerArea_); |
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| 116 | TrayVolume_ = 0.25*Pi*(TrayDiameter_^2)*TraySpacing_; |
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| 117 | HolesArea_ = 0.25*Pi*(TrayDiameter_^2)*Fraction_HoleArea_; |
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| 118 | |
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| 119 | EQUATIONS |
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| 120 | |
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| 121 | # LiquidFlow and VapourFlow equations need to be linerized to avoid indetermination ! |
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| 122 | switch LiquidFlow |
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| 123 | |
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| 124 | case "on": |
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| 125 | |
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| 126 | if LFlowModel equal 1 then |
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| 127 | "Francis Equation" |
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| 128 | OutletLiquid.F*vL = 1.84*'1/s'*WeirLength_*((Level-(AerationFraction_*WeirHeight_))/(AerationFraction_))^2; |
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| 129 | |
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| 130 | else if LFlowModel equal 2 then |
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| 131 | "Wang_Fl" |
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| 132 | OutletLiquid.F*vL = 1.84*'m^0.5/s'*WeirLength_*((Level-(AerationFraction_*WeirHeight_))/(AerationFraction_))^1.5; |
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| 133 | |
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| 134 | else if LFlowModel equal 3 then |
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| 135 | "Olsen" |
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| 136 | OutletLiquid.F / 'mol/s'= WeirLength_*TrayLiquidPasses_*rhoL/sum(Mw*OutletVapour.z)/(0.665*OlsenCoeff)^1.5 * ((ML*sum(Mw*OutletLiquid.z)/rhoL/PlateArea_)-WeirHeight_)^1.5 * 'm^0.5/mol'; |
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| 137 | |
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| 138 | else if LFlowModel equal 4 then |
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| 139 | "Feehery_Fl" |
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| 140 | OutletLiquid.F = WeirLength_*rhoL/sum(Mw*OutletLiquid.z) * ((Level-WeirHeight_)/750/'mm')^1.5 * 'm^2/s'; |
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| 141 | |
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| 142 | else |
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| 143 | "Roffel_Fl" |
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| 144 | OutletLiquid.F = 2/3*rhoL/sum(Mw*OutletLiquid.z)*WeirLength_*(ML*sum(Mw*OutletLiquid.z)/(PlateArea_*1.3)/rhoL)^1.5*sqrt(2*Gconst/ |
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| 145 | (2*(1 - 0.3593/'Pa^0.0888545'*abs(OutletVapour.F*sum(Mw*OutletVapour.z)/(PlateArea_*1.3)/sqrt(rhoV))^0.177709)-1)); #/'(kg/m)^0.0888545/s^0.177709'; |
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| 146 | end |
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| 147 | end |
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| 148 | end |
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| 149 | end |
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| 150 | |
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| 151 | when Level < (AerationFraction_ *WeirHeight_) switchto "off"; |
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| 152 | |
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| 153 | case "off": |
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| 154 | |
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| 155 | "Low level" |
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| 156 | OutletLiquid.F = zero_flow; |
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| 157 | |
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| 158 | when Level > (AerationFraction_ * WeirHeight_) switchto "on"; |
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| 159 | |
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| 160 | end |
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| 161 | |
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| 162 | switch VapourFlow |
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| 163 | |
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| 164 | case "on": |
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| 165 | |
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| 166 | if VFlowModel equal 1 then |
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| 167 | "Reepmeyer" |
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| 168 | InletVapour.F*vV = sqrt((InletVapour.P - OutletVapour.P)/(rhoV*DryPdropCoeff_))*HolesArea_; |
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| 169 | |
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| 170 | else if VFlowModel equal 2 then |
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| 171 | "Feehery_Fv" |
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| 172 | InletVapour.F = rhoV/PlateArea_/FeeheryCoeff/sum(Mw*OutletVapour.z) * sqrt(((InletVapour.P - OutletVapour.P)-(rhoV*Gconst*ML*vL/PlateArea_))/rhoV); |
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| 173 | |
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| 174 | else if VFlowModel equal 3 then |
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| 175 | "Roffel_Fv" |
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| 176 | InletVapour.F^1.08 * 0.0013 * 'kg/m/mol^1.08/s^0.92*1e5' = (InletVapour.P - OutletVapour.P)*1e5 - (AerationFraction_*sum(M*Mw)/(PlateArea_*1.3)*Gconst*1e5) * (rhoV*HolesArea_/sum(Mw*OutletVapour.z))^1.08 * 'm^1.08/mol^1.08'; |
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| 177 | |
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| 178 | else if VFlowModel equal 4 then |
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| 179 | "Klingberg" |
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| 180 | InletVapour.F * vV = PlateArea_ * sqrt(((InletVapour.P - OutletVapour.P)-rhoL*Gconst*Level)/rhoV); |
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| 181 | |
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| 182 | else if VFlowModel equal 5 then |
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| 183 | "Wang_Fv" |
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| 184 | InletVapour.F * vV = PlateArea_ * sqrt(((InletVapour.P - OutletVapour.P)-rhoL*Gconst*Level)/rhoV*DryPdropCoeff_); |
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| 185 | |
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| 186 | else |
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| 187 | "Elgue" |
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| 188 | InletVapour.F = sqrt((InletVapour.P - OutletVapour.P)/ElgueCoeff); |
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| 189 | end |
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| 190 | end |
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| 191 | end |
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| 192 | end |
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| 193 | end |
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| 194 | |
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| 195 | when InletVapour.F < low_flow switchto "off"; |
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| 196 | |
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| 197 | case "off": |
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| 198 | InletVapour.F = zero_flow; |
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| 199 | |
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| 200 | when InletVapour.P > OutletVapour.P switchto "on"; |
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| 201 | |
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| 202 | end |
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| 203 | |
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| 204 | "Murphree Efficiency" |
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| 205 | OutletVapour.z = MurphreeEff_ * (yideal - InletVapour.z) + InletVapour.z; |
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| 206 | |
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| 207 | "Energy Balance" |
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| 208 | diff(E) = ( Inlet.F*Inlet.h + InletLiquid.F*InletLiquid.h + InletVapour.F*InletVapour.h- OutletLiquid.F*OutletLiquid.h - OutletVapour.F*OutletVapour.h |
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| 209 | - VapourSideStream.F*VapourSideStream.h - LiquidSideStream.F*LiquidSideStream.h + HeatSupply_ ); |
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| 210 | |
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| 211 | "Energy Holdup" |
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| 212 | E = ML*OutletLiquid.h + MV*OutletVapour.h - OutletLiquid.P*TrayVolume_; |
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| 213 | |
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| 214 | "Geometry Constraint" |
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| 215 | TrayVolume_ = ML* vL + MV*vV; |
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| 216 | |
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| 217 | "Level of clear liquid over the weir" |
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| 218 | Level = ML*vL/PlateArea_; |
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| 219 | |
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| 220 | "Component Molar Balance" |
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| 221 | diff(M)=Inlet.F*Inlet.z + InletLiquid.F*InletLiquid.z + InletVapour.F*InletVapour.z- OutletLiquid.F*OutletLiquid.z - OutletVapour.F*OutletVapour.z- |
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| 222 | LiquidSideStream.F*LiquidSideStream.z-VapourSideStream.F*VapourSideStream.z; |
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| 223 | |
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| 224 | "Molar Holdup" |
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| 225 | M = ML*OutletLiquid.z + MV*OutletVapour.z; |
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| 226 | |
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| 227 | "Mol fraction normalisation" |
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| 228 | sum(OutletLiquid.z)= 1.0; |
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| 229 | |
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| 230 | "Mol fraction constraint" |
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| 231 | sum(OutletLiquid.z)= sum(OutletVapour.z); |
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| 232 | |
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| 233 | "Liquid Volume" |
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| 234 | vL = PP.LiquidVolume(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z); |
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| 235 | |
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| 236 | "Vapour Volume" |
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| 237 | vV = PP.VapourVolume(OutletVapour.T, OutletVapour.P, OutletVapour.z); |
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| 238 | |
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| 239 | "Liquid Density" |
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| 240 | rhoL = PP.LiquidDensity(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z); |
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| 241 | |
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| 242 | "Vapour Density" |
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| 243 | rhoV = PP.VapourDensity(InletVapour.T, InletVapour.P, InletVapour.z); |
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| 244 | |
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| 245 | "Chemical Equilibrium" |
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| 246 | PP.LiquidFugacityCoefficient(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z)*OutletLiquid.z = PP.VapourFugacityCoefficient(OutletVapour.T, OutletVapour.P, yideal)*yideal; |
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| 247 | |
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| 248 | "Thermal Equilibrium" |
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| 249 | OutletVapour.T = OutletLiquid.T; |
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| 250 | |
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| 251 | "Mechanical Equilibrium" |
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| 252 | OutletVapour.P = OutletLiquid.P; |
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| 253 | |
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| 254 | "Thermal Equilibrium Vapour Side Stream" |
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| 255 | OutletVapour.T = VapourSideStream.T; |
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| 256 | |
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| 257 | "Thermal Equilibrium Liquid Side Stream" |
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| 258 | OutletLiquid.T = LiquidSideStream.T; |
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| 259 | |
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| 260 | "Mechanical Equilibrium Vapour Side Stream" |
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| 261 | OutletVapour.P= VapourSideStream.P; |
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| 262 | |
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| 263 | "Mechanical Equilibrium Liquid Side Stream" |
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| 264 | OutletLiquid.P = LiquidSideStream.P; |
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| 265 | |
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| 266 | "Composition Liquid Side Stream" |
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| 267 | OutletLiquid.z= LiquidSideStream.z; |
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| 268 | |
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| 269 | "Composition Vapour Side Stream" |
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| 270 | OutletVapour.z= VapourSideStream.z; |
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| 271 | |
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| 272 | end |
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| 273 | |
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| 274 | #*------------------------------------------------------------------- |
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| 275 | * Model of a tray with reaction |
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| 276 | *-------------------------------------------------------------------*# |
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| 277 | Model trayReac |
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| 278 | ATTRIBUTES |
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| 279 | Pallete = false; |
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| 280 | Icon = "icon/Tray"; |
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| 281 | Brief = "Model of a tray with reaction."; |
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| 282 | Info = |
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| 283 | "== Assumptions == |
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| 284 | * both phases (liquid and vapour) exists all the time; |
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| 285 | * thermodymanic equilibrium with Murphree plate efficiency; |
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| 286 | * no entrainment of liquid or vapour phase; |
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| 287 | * no weeping; |
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| 288 | * the dymanics in the downcomer are neglected. |
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| 289 | |
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| 290 | == Specify == |
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| 291 | * the Feed stream; |
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| 292 | * the Liquid inlet stream; |
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| 293 | * the Vapour inlet stream; |
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| 294 | * the Vapour outlet flow (OutletVapour.F); |
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| 295 | * the reaction related variables. |
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| 296 | |
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| 297 | == Initial == |
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| 298 | * the plate temperature (OutletLiquid.T) |
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| 299 | * the liquid height (Level) OR the liquid flow OutletLiquid.F |
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| 300 | * (NoComps - 1) OutletLiquid compositions |
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| 301 | "; |
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| 302 | |
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| 303 | PARAMETERS |
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| 304 | |
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| 305 | outer PP as Plugin(Type="PP"); |
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| 306 | outer NComp as Integer; |
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| 307 | |
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| 308 | VARIABLES |
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| 309 | |
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| 310 | Inlet as stream (Brief="Feed stream", PosX=0, PosY=0.4932, Symbol="_{in}"); |
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| 311 | LiquidSideStream as liquid_stream (Brief="liquid Sidestream", Hidden=true, Symbol="_{outL}"); |
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| 312 | VapourSideStream as vapour_stream (Brief="vapour Sidestream", Hidden=true, Symbol="_{outV}"); |
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| 313 | |
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| 314 | |
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| 315 | in InletLiquid as stream (Brief="Inlet liquid stream", PosX=0.5195, PosY=0, Symbol="_{inL}"); |
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| 316 | in InletVapour as stream (Brief="Inlet vapour stream", PosX=0.4994, PosY=1, Symbol="_{inV}"); |
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| 317 | out OutletLiquid as liquid_stream (Brief="Outlet liquid stream", PosX=0.8277, PosY=1, Symbol="_{outL}"); |
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| 318 | out OutletVapour as vapour_stream (Brief="Outlet vapour stream", PosX=0.8043, PosY=0, Symbol="_{outV}"); |
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| 319 | |
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| 320 | yideal(NComp) as fraction; |
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| 321 | |
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| 322 | M(NComp) as mol (Brief="Molar Holdup in the tray"); |
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| 323 | ML as mol (Brief="Molar liquid holdup"); |
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| 324 | MV as mol (Brief="Molar vapour holdup"); |
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| 325 | E as energy (Brief="Total Energy Holdup on tray"); |
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| 326 | vL as volume_mol (Brief="Liquid Molar Volume"); |
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| 327 | vV as volume_mol (Brief="Vapour Molar volume"); |
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| 328 | Level as length (Brief="Height of clear liquid on plate"); |
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| 329 | Vol as volume; |
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| 330 | |
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| 331 | rhoL as dens_mass; |
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| 332 | rhoV as dens_mass; |
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| 333 | r3 as reaction_mol (Brief = "Reaction resulting ethyl acetate", DisplayUnit = 'mol/l/s'); |
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| 334 | C(NComp) as conc_mol (Brief = "Molar concentration", Lower = -1); |
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| 335 | |
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| 336 | EQUATIONS |
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| 337 | |
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| 338 | "Molar Concentration" |
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| 339 | OutletLiquid.z = vL * C; |
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| 340 | |
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| 341 | "Reaction" |
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| 342 | r3 = exp(-7150*'K'/OutletLiquid.T)*(4.85e4*C(1)*C(2) - 1.23e4*C(3)*C(4))*'l/mol/s'; |
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| 343 | |
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| 344 | "Molar Holdup" |
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| 345 | M = ML*OutletLiquid.z + MV*OutletVapour.z; |
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| 346 | |
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| 347 | "Thermal Equilibrium Vapour Side Stream" |
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| 348 | OutletVapour.T = VapourSideStream.T; |
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| 349 | |
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| 350 | "Thermal Equilibrium Liquid Side Stream" |
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| 351 | OutletLiquid.T = LiquidSideStream.T; |
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| 352 | |
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| 353 | "Mechanical Equilibrium Vapour Side Stream" |
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| 354 | OutletVapour.P= VapourSideStream.P; |
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| 355 | |
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| 356 | "Mechanical Equilibrium Liquid Side Stream" |
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| 357 | OutletLiquid.P = LiquidSideStream.P; |
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| 358 | |
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| 359 | "Composition Liquid Side Stream" |
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| 360 | OutletLiquid.z= LiquidSideStream.z; |
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| 361 | |
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| 362 | "Composition Vapour Side Stream" |
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| 363 | OutletVapour.z= VapourSideStream.z; |
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| 364 | |
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| 365 | "Mol fraction normalisation" |
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| 366 | sum(OutletLiquid.z)= 1.0; |
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| 367 | |
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| 368 | "Liquid Volume" |
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| 369 | vL = PP.LiquidVolume(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z); |
---|
| 370 | |
---|
| 371 | "Vapour Volume" |
---|
| 372 | vV = PP.VapourVolume(OutletVapour.T, OutletVapour.P, OutletVapour.z); |
---|
| 373 | |
---|
| 374 | "Thermal Equilibrium" |
---|
| 375 | OutletVapour.T = OutletLiquid.T; |
---|
| 376 | |
---|
| 377 | "Mechanical Equilibrium" |
---|
| 378 | OutletVapour.P = OutletLiquid.P; |
---|
| 379 | |
---|
| 380 | Vol = ML*vL; |
---|
| 381 | |
---|
| 382 | "Liquid Density" |
---|
| 383 | rhoL = PP.LiquidDensity(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z); |
---|
| 384 | |
---|
| 385 | "Vapour Density" |
---|
| 386 | rhoV = PP.VapourDensity(InletVapour.T, InletVapour.P, InletVapour.z); |
---|
| 387 | |
---|
| 388 | "Chemical Equilibrium" |
---|
| 389 | PP.LiquidFugacityCoefficient(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z)*OutletLiquid.z = PP.VapourFugacityCoefficient(OutletVapour.T, OutletVapour.P, yideal)*yideal; |
---|
| 390 | |
---|
| 391 | sum(OutletLiquid.z)= sum(OutletVapour.z); |
---|
| 392 | |
---|
| 393 | end |
---|
| 394 | |
---|
| 395 | #*------------------------------------- |
---|
| 396 | * Model of a packed column stage |
---|
| 397 | -------------------------------------*# |
---|
| 398 | Model packedStage |
---|
| 399 | |
---|
| 400 | ATTRIBUTES |
---|
| 401 | Pallete = false; |
---|
| 402 | Brief = "Complete model of a packed column stage."; |
---|
| 403 | Info = |
---|
| 404 | "== Specify == |
---|
| 405 | * the Feed stream |
---|
| 406 | * the Liquid inlet stream |
---|
| 407 | * the Vapour inlet stream |
---|
| 408 | * the stage pressure drop (deltaP) |
---|
| 409 | |
---|
| 410 | == Initial == |
---|
| 411 | * the plate temperature (OutletLiquid.T) |
---|
| 412 | * the liquid molar holdup ML |
---|
| 413 | * (NoComps - 1) OutletLiquid compositions |
---|
| 414 | "; |
---|
| 415 | |
---|
| 416 | PARAMETERS |
---|
| 417 | |
---|
| 418 | outer PP as Plugin (Brief = "External Physical Properties", Type="PP"); |
---|
| 419 | outer NComp as Integer (Brief = "Number Of Components"); |
---|
| 420 | |
---|
| 421 | LiquidResistanceCoeff as positive (Brief="Resistance coefficient on the liquid load", Default=1,Hidden=true); |
---|
| 422 | AreaPerPackingVolume as Real (Brief="surface area per packing volume", Unit='m^2/m^3',Hidden=true); |
---|
| 423 | ColumnInternalDiameter as length (Brief="Column diameter",Hidden=true); |
---|
| 424 | PackingVoidFraction as Real (Brief="Void fraction of packing, (m^3 void space/m^3 packed bed)",Hidden=true); |
---|
| 425 | HeightOfPacking as length (Brief="Height of packing",Hidden=true); |
---|
| 426 | Number_Stages as Integer (Brief="Number of Stages", Default=3,Hidden=true); |
---|
| 427 | HeatOnStage as heat_rate (Brief="Rate of heat supply",Hidden=true); |
---|
| 428 | |
---|
| 429 | HETP as length (Brief="The Height Equivalent to a Theoretical Plate",Hidden=true); |
---|
| 430 | ColumnArea as area (Brief="Column Sectional Cross Area",Hidden=true); |
---|
| 431 | V as volume (Brief="Total Volume of the tray",Hidden=true); |
---|
| 432 | Pi as constant (Brief="Pi Number",Default=3.14159265, Symbol = "\pi",Hidden=true); |
---|
| 433 | Gconst as acceleration (Brief="Gravity Acceleration",Default=9.81,Hidden=true); |
---|
| 434 | |
---|
| 435 | low_flow as flow_mol (Brief ="Low Flow",Default = 1E-6, Hidden=true); |
---|
| 436 | low_pressure as pressure (Brief ="Low Pressure",Default = 1E-6, Hidden=true); |
---|
| 437 | zero_flow as flow_mol (Brief ="No Flow",Default = 0, Hidden=true); |
---|
| 438 | |
---|
| 439 | Mw(NComp) as molweight (Brief = "Component Mol Weight",Hidden=true); |
---|
| 440 | VapourFlow as Switcher (Brief = "Vapour Flow", Valid = ["on", "off"], Default = "on",Hidden=true); |
---|
| 441 | |
---|
| 442 | SET |
---|
| 443 | Mw = PP.MolecularWeight(); |
---|
| 444 | |
---|
| 445 | ColumnArea = 0.25*Pi*ColumnInternalDiameter^2; |
---|
| 446 | HETP = HeightOfPacking/Number_Stages; |
---|
| 447 | V = HETP * ColumnArea; |
---|
| 448 | |
---|
| 449 | low_pressure = 1E-4 * 'atm'; |
---|
| 450 | low_flow = 1E-6 * 'kmol/h'; |
---|
| 451 | zero_flow = 0 * 'kmol/h'; |
---|
| 452 | |
---|
| 453 | VARIABLES |
---|
| 454 | |
---|
| 455 | Inlet as stream (Brief="Feed stream", Symbol="_{in}",Protected=true); |
---|
| 456 | in InletLiquid as stream (Brief="Inlet liquid stream", Symbol="_{inL}",Protected=true); |
---|
| 457 | in InletVapour as stream (Brief="Inlet vapour stream", Symbol="_{inV}",Protected=true); |
---|
| 458 | out OutletLiquid as liquid_stream (Brief="Outlet liquid stream", Symbol="_{outL}",Protected=true); |
---|
| 459 | out OutletVapour as vapour_stream (Brief="Outlet vapour stream", Symbol="_{outV}",Protected=true); |
---|
| 460 | |
---|
| 461 | M(NComp) as mol (Brief="Molar Holdup in the tray", Default=0.01, Lower=-0.000001, Upper=100,Protected=true); |
---|
| 462 | ML as mol (Brief="Molar liquid holdup", Default=0.01, Lower=0, Upper=100,Protected=true); |
---|
| 463 | MV as mol (Brief="Molar vapour holdup", Default=0.01, Lower=0, Upper=100,Protected=true); |
---|
| 464 | E as energy (Brief="Total Energy Holdup on tray", Default=-500,Protected=true); |
---|
| 465 | vL as volume_mol (Brief="Liquid Molar Volume",Protected=true); |
---|
| 466 | vV as volume_mol (Brief="Vapour Molar volume",Protected=true); |
---|
| 467 | miL as viscosity (Brief="Liquid dynamic viscosity", DisplayUnit='kg/m/s',Protected=true); |
---|
| 468 | rhoL as dens_mass (Brief="Liquid mass density",Protected=true); |
---|
| 469 | rhoV as dens_mass (Brief="Vapour mass density",Protected=true); |
---|
| 470 | uL as velocity (Brief="volume flow rate of liquid, m^3/m^2/s", Lower=-10, Upper=1000,Protected=true); |
---|
| 471 | uV as velocity (Brief="volume flow rate of vapor, m^3/m^2/s", Lower=-10, Upper=1000,Protected=true); |
---|
| 472 | Al as area (Brief="Area occupied by the liquid", Default=0.001, Upper=10,Protected=true); |
---|
| 473 | hl as positive (Brief="Column holdup", Unit='m^3/m^3', Default=0.01,Upper=10,Protected=true); |
---|
| 474 | deltaP as pressure (Brief="Stage Pressure drop",Protected=true); |
---|
| 475 | |
---|
| 476 | EQUATIONS |
---|
| 477 | |
---|
| 478 | switch VapourFlow |
---|
| 479 | |
---|
| 480 | case "on": |
---|
| 481 | "Pressure drop and Vapor flow, Billet (4-58)" |
---|
| 482 | deltaP/HETP = LiquidResistanceCoeff *( 0.5*AreaPerPackingVolume + 2/ColumnInternalDiameter) * 1/((PackingVoidFraction-hl)^3) * (uV^2) *rhoV; |
---|
| 483 | |
---|
| 484 | when InletVapour.F < low_flow switchto "off"; |
---|
| 485 | |
---|
| 486 | case "off": |
---|
| 487 | "Vapour Flow" |
---|
| 488 | InletVapour.F = zero_flow; |
---|
| 489 | |
---|
| 490 | when deltaP > low_pressure switchto "on"; |
---|
| 491 | |
---|
| 492 | end |
---|
| 493 | |
---|
| 494 | "Energy Balance" |
---|
| 495 | diff(E) = (Inlet.F*Inlet.h + InletLiquid.F*InletLiquid.h + InletVapour.F*InletVapour.h- OutletLiquid.F*OutletLiquid.h |
---|
| 496 | - OutletVapour.F*OutletVapour.h + HeatOnStage ); |
---|
| 497 | |
---|
| 498 | "Energy Holdup" |
---|
| 499 | E = ML*OutletLiquid.h + MV*OutletVapour.h - OutletLiquid.P*V; |
---|
| 500 | |
---|
| 501 | "Geometry Constraint" |
---|
| 502 | V*PackingVoidFraction= ML*vL + MV*vV; |
---|
| 503 | |
---|
| 504 | "Volume flow rate of vapor, m^3/m^2/s" |
---|
| 505 | uV * (V*PackingVoidFraction/HETP - Al) = InletVapour.F * vV; |
---|
| 506 | |
---|
| 507 | "Liquid holdup" |
---|
| 508 | hl*V*PackingVoidFraction = ML*vL; |
---|
| 509 | |
---|
| 510 | "Liquid velocity as a function of liquid holdup, Billet (4-27)" |
---|
| 511 | hl^3 = (12/Gconst) * AreaPerPackingVolume^2 * (miL/rhoL) * uL; |
---|
| 512 | |
---|
| 513 | "Area occupied by the liquid" |
---|
| 514 | Al = ML*vL/HETP; |
---|
| 515 | |
---|
| 516 | "Component Molar Balance" |
---|
| 517 | diff(M)=Inlet.F*Inlet.z + InletLiquid.F*InletLiquid.z + InletVapour.F*InletVapour.z- OutletLiquid.F*OutletLiquid.z - OutletVapour.F*OutletVapour.z; |
---|
| 518 | |
---|
| 519 | "Molar Holdup" |
---|
| 520 | M = ML*OutletLiquid.z + MV*OutletVapour.z; |
---|
| 521 | |
---|
| 522 | "Mol Fraction Normalisation" |
---|
| 523 | sum(OutletLiquid.z)= 1.0; |
---|
| 524 | |
---|
| 525 | "Mol Fraction Constraint" |
---|
| 526 | sum(OutletLiquid.z)= sum(OutletVapour.z); |
---|
| 527 | |
---|
| 528 | "Liquid Volume" |
---|
| 529 | vL = PP.LiquidVolume(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z); |
---|
| 530 | |
---|
| 531 | "Vapour Volume" |
---|
| 532 | vV = PP.VapourVolume(OutletVapour.T, OutletVapour.P, OutletVapour.z); |
---|
| 533 | |
---|
| 534 | "Chemical Equilibrium" |
---|
| 535 | PP.LiquidFugacityCoefficient(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z)*OutletLiquid.z = PP.VapourFugacityCoefficient(OutletVapour.T, OutletVapour.P, OutletVapour.z)*OutletVapour.z; |
---|
| 536 | |
---|
| 537 | "Thermal Equilibrium" |
---|
| 538 | OutletVapour.T = OutletLiquid.T; |
---|
| 539 | |
---|
| 540 | "Mechanical Equilibrium" |
---|
| 541 | OutletLiquid.P = OutletVapour.P; |
---|
| 542 | |
---|
| 543 | "Liquid Density" |
---|
| 544 | rhoL = PP.LiquidDensity(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z); |
---|
| 545 | |
---|
| 546 | "Vapour Density" |
---|
| 547 | rhoV = PP.VapourDensity(InletVapour.T, InletVapour.P, InletVapour.z); |
---|
| 548 | |
---|
| 549 | "Liquid viscosity" |
---|
| 550 | miL = PP.LiquidViscosity(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z); |
---|
| 551 | |
---|
| 552 | "Volume flow rate of liquid, m^3/m^2/s" |
---|
| 553 | uL * Al = OutletLiquid.F * vL; |
---|
| 554 | |
---|
| 555 | "Pressure Drop" |
---|
| 556 | deltaP = InletVapour.P - OutletVapour.P; |
---|
| 557 | |
---|
| 558 | end |
---|
| 559 | |
---|
| 560 | #*------------------------------------- |
---|
| 561 | * Nonequilibrium Model |
---|
| 562 | -------------------------------------* |
---|
| 563 | Model interfaceTeste |
---|
| 564 | |
---|
| 565 | ATTRIBUTES |
---|
| 566 | Pallete = false; |
---|
| 567 | Icon = "icon/Tray"; |
---|
| 568 | Brief = "Descrition of variables of the equilibrium interface."; |
---|
| 569 | Info = |
---|
| 570 | "This model contains only the variables of the equilibrium interface."; |
---|
| 571 | |
---|
| 572 | PARAMETERS |
---|
| 573 | outer PP as Plugin(Brief = "External Physical Properties", Type="PP"); |
---|
| 574 | outer NComp as Integer; |
---|
| 575 | outer NC1 as Integer; |
---|
| 576 | |
---|
| 577 | VARIABLES |
---|
| 578 | NL(NComp) as flow_mol_delta (Brief = "Stream Molar Rate on Liquid Phase"); |
---|
| 579 | NV(NComp) as flow_mol_delta (Brief = "Stream Molar Rate on Vapour Phase"); |
---|
| 580 | T as temperature (Brief = "Stream Temperature"); |
---|
| 581 | P as pressure (Brief = "Stream Pressure"); |
---|
| 582 | x(NComp) as fraction (Brief = "Stream Molar Fraction on Liquid Phase"); |
---|
| 583 | y(NComp) as fraction (Brief = "Stream Molar Fraction on Vapour Phase"); |
---|
| 584 | a as area (Brief = "Interface Area"); |
---|
| 585 | htL as heat_trans_coeff (Brief = "Heat Transference Coefficient on Liquid Phase"); |
---|
| 586 | htV as heat_trans_coeff (Brief = "Heat Transference Coefficient on Vapour Phase"); |
---|
| 587 | E_liq as heat_rate (Brief = "Liquid Energy Rate at interface"); |
---|
| 588 | E_vap as heat_rate (Brief = "Vapour Energy Rate at interface"); |
---|
| 589 | hL as enth_mol (Brief = "Liquid Molar Enthalpy"); |
---|
| 590 | hV as enth_mol (Brief = "Vapour Molar Enthalpy"); |
---|
| 591 | kL(NC1,NC1) as velocity (Brief = "Mass Transfer Coefficients"); |
---|
| 592 | kV(NC1,NC1) as velocity (Brief = "Mass Transfer Coefficients"); |
---|
| 593 | |
---|
| 594 | EQUATIONS |
---|
| 595 | "Liquid Enthalpy" |
---|
| 596 | hL = PP.LiquidEnthalpy(T, P, x); |
---|
| 597 | |
---|
| 598 | "Vapour Enthalpy" |
---|
| 599 | hV = PP.VapourEnthalpy(T, P, y); |
---|
| 600 | |
---|
| 601 | end |
---|
| 602 | |
---|
| 603 | Model trayRateBasicTeste |
---|
| 604 | ATTRIBUTES |
---|
| 605 | Pallete = false; |
---|
| 606 | Icon = "icon/Tray"; |
---|
| 607 | Brief = "Basic equations of a tray rate column model."; |
---|
| 608 | Info = |
---|
| 609 | "This model contains only the main equations of a column tray nonequilibrium model without |
---|
| 610 | the hidraulic equations. |
---|
| 611 | |
---|
| 612 | == Assumptions == |
---|
| 613 | * both phases (liquid and vapour) exists all the time; |
---|
| 614 | * no entrainment of liquid or vapour phase; |
---|
| 615 | * no weeping; |
---|
| 616 | * the dymanics in the downcomer are neglected. |
---|
| 617 | "; |
---|
| 618 | |
---|
| 619 | PARAMETERS |
---|
| 620 | outer PP as Plugin(Brief = "External Physical Properties", Type="PP"); |
---|
| 621 | outer NComp as Integer; |
---|
| 622 | NC1 as Integer; |
---|
| 623 | V as volume(Brief="Total Volume of the tray"); |
---|
| 624 | Q as heat_rate (Brief="Rate of heat supply"); |
---|
| 625 | Ap as area (Brief="Plate area = Atray - Adowncomer"); |
---|
| 626 | |
---|
| 627 | VARIABLES |
---|
| 628 | in Inlet as stream (Brief="Feed stream", PosX=0, PosY=0.4932, Symbol="_{in}"); |
---|
| 629 | in InletFV as stream (Brief="Feed stream", PosX=0, PosY=0.4932, Symbol="_{in}"); |
---|
| 630 | in InletLiquid as stream (Brief="Inlet liquid stream", PosX=0.5195, PosY=0, Symbol="_{inL}"); |
---|
| 631 | in InletVapour as stream (Brief="Inlet vapour stream", PosX=0.4994, PosY=1, Symbol="_{inV}"); |
---|
| 632 | out OutletLiquid as liquid_stream (Brief="Outlet liquid stream", PosX=0.8277, PosY=1, Symbol="_{outL}"); |
---|
| 633 | out OutletVapour as vapour_stream (Brief="Outlet vapour stream", PosX=0.8043, PosY=0, Symbol="_{outV}"); |
---|
| 634 | |
---|
| 635 | M_liq(NComp) as mol (Brief="Liquid Molar Holdup in the tray"); |
---|
| 636 | M_vap(NComp) as mol (Brief="Vapour Molar Holdup in the tray"); |
---|
| 637 | ML as mol (Brief="Molar liquid holdup"); |
---|
| 638 | MV as mol (Brief="Molar vapour holdup"); |
---|
| 639 | E_liq as energy (Brief="Total Liquid Energy Holdup on tray"); |
---|
| 640 | E_vap as energy (Brief="Total Vapour Energy Holdup on tray"); |
---|
| 641 | vL as volume_mol (Brief="Liquid Molar Volume"); |
---|
| 642 | vV as volume_mol (Brief="Vapour Molar volume"); |
---|
| 643 | Level as length (Brief="Height of clear liquid on plate"); |
---|
| 644 | interf as interfaceTeste; |
---|
| 645 | |
---|
| 646 | SET |
---|
| 647 | NC1=NComp-1; |
---|
| 648 | |
---|
| 649 | EQUATIONS |
---|
| 650 | "Component Molar Balance" |
---|
| 651 | diff(M_liq)=Inlet.F*Inlet.z + InletLiquid.F*InletLiquid.z |
---|
| 652 | - OutletLiquid.F*OutletLiquid.z + interf.NL; |
---|
| 653 | |
---|
| 654 | diff(M_vap)=InletFV.F*InletFV.z + InletVapour.F*InletVapour.z |
---|
| 655 | - OutletVapour.F*OutletVapour.z - interf.NV; |
---|
| 656 | |
---|
| 657 | "Energy Balance" |
---|
| 658 | diff(E_liq) = Inlet.F*Inlet.h + InletLiquid.F*InletLiquid.h |
---|
| 659 | - OutletLiquid.F*OutletLiquid.h + Q + interf.E_liq; |
---|
| 660 | |
---|
| 661 | diff(E_vap) = InletFV.F*InletFV.h + InletVapour.F*InletVapour.h |
---|
| 662 | - OutletVapour.F*OutletVapour.h - interf.E_vap; |
---|
| 663 | |
---|
| 664 | "Molar Holdup" |
---|
| 665 | M_liq = ML*OutletLiquid.z; |
---|
| 666 | |
---|
| 667 | M_vap = MV*OutletVapour.z; |
---|
| 668 | |
---|
| 669 | "Energy Holdup" |
---|
| 670 | E_liq = ML*(OutletLiquid.h - OutletLiquid.P*vL); |
---|
| 671 | |
---|
| 672 | E_vap = MV*(OutletVapour.h - OutletVapour.P*vV); |
---|
| 673 | |
---|
| 674 | "Energy Rate through the interface" |
---|
| 675 | interf.E_liq = interf.htL*interf.a*(interf.T-OutletLiquid.T)+sum(interf.NL)*interf.hL; |
---|
| 676 | |
---|
| 677 | interf.E_vap = interf.htV*interf.a*(OutletVapour.T-interf.T)+sum(interf.NV)*interf.hV; |
---|
| 678 | |
---|
| 679 | "Mass Conservation" |
---|
| 680 | interf.NL = interf.NV; |
---|
| 681 | |
---|
| 682 | "Energy Conservation" |
---|
| 683 | interf.E_liq = interf.E_vap; |
---|
| 684 | |
---|
| 685 | "Mol fraction normalisation" |
---|
| 686 | sum(OutletLiquid.z)= 1.0; |
---|
| 687 | sum(OutletLiquid.z)= sum(OutletVapour.z); |
---|
| 688 | sum(interf.x)=1.0; |
---|
| 689 | sum(interf.x)=sum(interf.y); |
---|
| 690 | |
---|
| 691 | "Liquid Volume" |
---|
| 692 | vL = PP.LiquidVolume(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z); |
---|
| 693 | "Vapour Volume" |
---|
| 694 | vV = PP.VapourVolume(OutletVapour.T, OutletVapour.P, OutletVapour.z); |
---|
| 695 | |
---|
| 696 | "Chemical Equilibrium" |
---|
| 697 | PP.LiquidFugacityCoefficient(interf.T, interf.P, interf.x)*interf.x = |
---|
| 698 | PP.VapourFugacityCoefficient(interf.T, interf.P, interf.y)*interf.y; |
---|
| 699 | |
---|
| 700 | "Geometry Constraint" |
---|
| 701 | V = ML*vL + MV*vV; |
---|
| 702 | |
---|
| 703 | "Level of clear liquid over the weir" |
---|
| 704 | Level = ML*vL/Ap; |
---|
| 705 | |
---|
| 706 | "Total Mass Transfer Rates" |
---|
| 707 | interf.NL(1:NC1)=interf.a*sumt(interf.kL*(interf.x(1:NC1)-OutletLiquid.z(1:NC1)))/vL+ |
---|
| 708 | OutletLiquid.z(1:NC1)*sum(interf.NL); |
---|
| 709 | |
---|
| 710 | # interf.NL(1:NC1)=0.01*'kmol/s'; |
---|
| 711 | |
---|
| 712 | interf.NV(1:NC1)=interf.a*sumt(interf.kV*(OutletVapour.z(1:NC1)-interf.y(1:NC1)))/vV+ |
---|
| 713 | OutletVapour.z(1:NC1)*sum(interf.NV); |
---|
| 714 | |
---|
| 715 | "Mechanical Equilibrium" |
---|
| 716 | OutletVapour.P = OutletLiquid.P; |
---|
| 717 | interf.P=OutletLiquid.P; |
---|
| 718 | end |
---|
| 719 | |
---|
| 720 | Model trayRateTeste as trayRateBasicTeste |
---|
| 721 | ATTRIBUTES |
---|
| 722 | Pallete = false; |
---|
| 723 | Icon = "icon/Tray"; |
---|
| 724 | Brief = "Complete rate model of a column tray."; |
---|
| 725 | Info = |
---|
| 726 | "== Specify == |
---|
| 727 | * the Feed stream |
---|
| 728 | * the Liquid inlet stream |
---|
| 729 | * the Vapour inlet stream |
---|
| 730 | * the Vapour outlet flow (OutletVapour.F) |
---|
| 731 | |
---|
| 732 | == Initial == |
---|
| 733 | * the plate temperature of both phases (OutletLiquid.T and OutletVapour.T) |
---|
| 734 | * the liquid height (Level) OR the liquid flow holdup (ML) |
---|
| 735 | * the vapor holdup (MV) |
---|
| 736 | * (NoComps - 1) OutletLiquid compositions |
---|
| 737 | "; |
---|
| 738 | |
---|
| 739 | PARAMETERS |
---|
| 740 | Ah as area (Brief="Total holes area"); |
---|
| 741 | lw as length (Brief="Weir length"); |
---|
| 742 | g as acceleration (Default=9.81); |
---|
| 743 | hw as length (Brief="Weir height"); |
---|
| 744 | beta as fraction (Brief="Aeration fraction"); |
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| 745 | alfa as fraction (Brief="Dry pressure drop coefficient"); |
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| 746 | |
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| 747 | VapourFlow as Switcher(Valid = ["on", "off"], Default = "on"); |
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| 748 | LiquidFlow as Switcher(Valid = ["on", "off"], Default = "on"); |
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| 749 | |
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| 750 | VARIABLES |
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| 751 | rhoL as dens_mass; |
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| 752 | rhoV as dens_mass; |
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| 753 | |
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| 754 | EQUATIONS |
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| 755 | "Liquid Density" |
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| 756 | rhoL = PP.LiquidDensity(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z); |
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| 757 | "Vapour Density" |
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| 758 | rhoV = PP.VapourDensity(InletVapour.T, InletVapour.P, InletVapour.z); |
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| 759 | |
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| 760 | switch LiquidFlow |
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| 761 | case "on": |
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| 762 | "Francis Equation" |
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| 763 | # OutletLiquid.F*vL = 1.84*'m^0.5/s'*lw*((Level-(beta*hw))/(beta))^1.5; |
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| 764 | OutletLiquid.F*vL = 1.84*'1/s'*lw*((Level-(beta*hw))/(beta))^2; |
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| 765 | when Level < (beta * hw) switchto "off"; |
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| 766 | |
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| 767 | case "off": |
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| 768 | "Low level" |
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| 769 | OutletLiquid.F = 0 * 'mol/h'; |
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| 770 | when Level > (beta * hw) + 1e-6*'m' switchto "on"; |
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| 771 | end |
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| 772 | |
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| 773 | switch VapourFlow |
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| 774 | case "on": |
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| 775 | InletVapour.F*vV = sqrt((InletVapour.P - OutletVapour.P)/(rhoV*alfa))*Ah; |
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| 776 | when InletVapour.F < 1e-6 * 'kmol/h' switchto "off"; |
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| 777 | |
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| 778 | case "off": |
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| 779 | InletVapour.F = 0 * 'mol/s'; |
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| 780 | when InletVapour.P > OutletVapour.P + Level*g*rhoL + 1e-1 * 'atm' switchto "on"; |
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| 781 | end |
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| 782 | end |
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| 783 | |
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| 784 | *# |
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