[420] | 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 | * Author: Gerson Balbueno Bicca |
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| 16 | * $Id: HeatExchangerDetailed.mso 197 2007-03-08 14:31:57Z bicca $ |
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| 17 | *------------------------------------------------------------------*# |
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| 18 | using "heat_exchangers/HEX_Engine"; |
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| 19 | |
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| 20 | Model ShellandTubesBasic |
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| 21 | |
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| 22 | ATTRIBUTES |
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| 23 | Pallete = false; |
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| 24 | Brief = "Basic Model for Detailed Shell and Tubes Heat Exchangers"; |
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| 25 | Info = |
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| 26 | "to be documented."; |
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| 27 | |
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| 28 | PARAMETERS |
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| 29 | |
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| 30 | HotSide as Switcher (Brief="Hot Side in the Exchanger",Valid=["shell","tubes"],Default="shell"); |
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| 31 | ShellType as Switcher (Brief="TEMA Designation",Valid=["Eshell","Fshell"],Default="Eshell"); |
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| 32 | |
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| 33 | VARIABLES |
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| 34 | |
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| 35 | in InletTube as stream (Brief="Inlet Tube Stream", PosX=0.08, PosY=0, Symbol="_{inTube}"); |
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| 36 | out OutletTube as streamPH (Brief="Outlet Tube Stream", PosX=0.08, PosY=1, Symbol="_{outTube}"); |
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| 37 | in InletShell as stream (Brief="Inlet Shell Stream", PosX=0.2237, PosY=0, Symbol="_{inShell}"); |
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| 38 | out OutletShell as streamPH (Brief="Outlet Shell Stream", PosX=0.8237, PosY=1, Symbol="_{outShell}"); |
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| 39 | |
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| 40 | Details as Details_Main (Brief="Details in Heat Exchanger"); |
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| 41 | Tubes as Tube_Side_Main (Brief="Tube Side"); |
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| 42 | Shell as Shell_Side_Main (Brief="Shell Side"); |
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| 43 | Baffles as Baffles_Main (Brief="Baffles"); |
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| 44 | |
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| 45 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 46 | # Auxiliar Variables - Must be hidden |
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| 47 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 48 | Nc as Real (Brief = "Number of Tube rows Crossed in one Crossflow Section",Lower=1); |
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| 49 | Ncw as Real (Brief = "Number of Effective Crossflow rows in Each Window",Lower=1); |
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| 50 | a as Real (Brief = "Variable for calculating Ji heat transfer correction Factor",Lower=1e-3); |
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| 51 | b as Real (Brief = "Variable for calculating shell side pressure drop friction Factor",Lower=1e-3); |
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| 52 | Rb as Real (Brief = "ByPass Correction Factor for Pressure Drop",Lower=1e-3); |
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| 53 | Rss as Real (Brief = "Correction Factor for Pressure Drop",Lower=1e-3); |
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| 54 | Rspd as Real (Brief = "Pressure Drop Correction Factor for Unequal Baffle Spacing",Lower=1e-3); |
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| 55 | mw as Real (Brief = "Mass Velocity in Window Zone", Unit='kg/m^2/s'); |
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| 56 | |
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| 57 | PARAMETERS |
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| 58 | outer PP as Plugin (Brief="External Physical Properties",Type = "PP"); |
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| 59 | outer NComp as Integer (Brief="Number of Components"); |
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| 60 | |
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| 61 | Pi as constant (Brief="Pi Number",Default=3.14159265); |
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| 62 | M(NComp) as molweight (Brief="Component Mol Weight"); |
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| 63 | |
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| 64 | TubeFlowRegime as Switcher (Brief="Tube Side Flow Regime ",Valid=["laminar","transition","turbulent"],Default="laminar"); |
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| 65 | ShellFlowRegime as Switcher (Brief="Shell Side Flow Regime ",Valid=["deep laminar","laminar","turbulent"],Default="deep laminar"); |
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| 66 | ShellRange as Switcher (Brief="Shell Side Flow Regime Range for Correction Factor",Valid=["range1","range2","range3", "range4","range5"],Default="range1"); |
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| 67 | Side as Switcher (Brief="Flag for Fluid Alocation ",Valid=["shell","tubes"],Default="shell"); |
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| 68 | LaminarCorrelation as Switcher (Brief="Tube Heat Transfer Correlation in Laminar Flow",Valid=["Hausen","Schlunder"],Default="Hausen"); |
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| 69 | TransitionCorrelation as Switcher (Brief="Tube Heat Transfer Correlation in Transition Flow",Valid=["Gnielinski","ESDU"],Default="Gnielinski"); |
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| 70 | TurbulentCorrelation as Switcher (Brief="Tube Heat Transfer Correlation in Turbulent Flow",Valid=["Petukhov","SiederTate"],Default="Petukhov"); |
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| 71 | |
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| 72 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 73 | # Shell Geometrical Parameters |
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| 74 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 75 | Tpass as Integer (Brief="Number of Tube Passes",Lower=1); |
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| 76 | Nss as Integer (Brief="Number of Sealing Strips pairs",Lower=1); |
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| 77 | Dishell as length (Brief="Inside Shell Diameter",Lower=10e-6); |
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| 78 | Donozzle_Shell as length (Brief="Shell Outlet Nozzle Diameter",Lower=10e-6); |
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| 79 | Dinozzle_Shell as length (Brief="Shell Inlet Nozzle Diameter",Lower=10e-6); |
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| 80 | Aonozzle_Shell as area (Brief="Shell Outlet Nozzle Area",Lower=10e-6); |
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| 81 | Ainozzle_Shell as area (Brief="Shell Inlet Nozzle Area",Lower=10e-6); |
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| 82 | Aeonozzle_Shell as area (Brief="Shell Outlet Escape Area Under Nozzle",Lower=10e-6); |
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| 83 | Aeinozzle_Shell as area (Brief="Shell Inlet Escape Area Under Nozzle",Lower=10e-6); |
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| 84 | Hinozzle_Shell as length (Brief="Height Under Shell Inlet Nozzle",Lower=10e-6); |
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| 85 | Honozzle_Shell as length (Brief="Height Under Shell Outlet Nozzle",Lower=10e-6); |
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| 86 | Lcf as length (Brief="Bundle-to-Shell Clearance",Lower=10e-8); |
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| 87 | |
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| 88 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 89 | # Tubes Geometrical Parameters |
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| 90 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 91 | Ntt as Integer (Brief="Total Number of Tubes in Shell",Default=100,Lower=1); |
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| 92 | Pattern as Switcher (Brief="Tube Layout Characteristic Angle",Valid=["Triangle","Rotated Square","Square"],Default="Triangle"); |
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| 93 | Ltube as length (Brief="Effective Tube Length",Lower=0.1); |
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| 94 | pitch as length (Brief="Tube Pitch",Lower=1e-8); |
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| 95 | Kwall as conductivity (Brief="Tube Wall Material Thermal Conductivity"); |
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| 96 | Dotube as length (Brief="Tube Outside Diameter",Lower=10e-6); |
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| 97 | Ditube as length (Brief="Tube Inside Diameter",Lower=10e-6); |
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| 98 | Donozzle_Tube as length (Brief="Tube Outlet Nozzle Diameter",Lower=10e-6); |
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| 99 | Dinozzle_Tube as length (Brief="Tube Inlet Nozzle Diameter",Lower=10e-6); |
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| 100 | Aonozzle_Tube as area (Brief="Tube Outlet Nozzle Area",Lower=10e-6); |
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| 101 | Ainozzle_Tube as area (Brief="Tube Inlet Nozzle Area",Lower=10e-6); |
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| 102 | Kinlet_Tube as positive (Brief="Tube Inlet Nozzle Pressure Loss Coeff",Default=1.1); |
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| 103 | Koutlet_Tube as positive (Brief="Tube Outlet Nozzle Pressure Loss Coeff",Default=0.7); |
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| 104 | |
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| 105 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 106 | # Baffles Geometrical Parameters |
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| 107 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 108 | Bc as Integer (Brief="Baffle Cut",Default=25,Lower=25); |
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| 109 | Nb as Real (Brief="Number of Baffles",Lower=1); |
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| 110 | Lcd as length (Brief="Baffle-to-Shell Clearance",Lower=10e-8); |
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| 111 | Ltd as length (Brief="Tube-to-Bafflehole Clearance",Lower=10e-8); |
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| 112 | |
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| 113 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 114 | # Fouling |
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| 115 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 116 | Rfi as positive (Brief="Inside Fouling Resistance",Unit='m^2*K/kW',Default=1e-6,Lower=0); |
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| 117 | Rfo as positive (Brief="Outside Fouling Resistance",Unit='m^2*K/kW',Default=1e-6,Lower=0); |
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| 118 | |
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| 119 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 120 | # Auxiliar Parameters - Must be hidden |
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| 121 | #+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# |
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| 122 | Ods as Real (Brief="Baffle Cut Angle in Degrees"); |
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| 123 | Octl as Real (Brief="Baffle Cut Angle relative to the centerline in Degrees"); |
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| 124 | Ftw as Real (Brief="Fraction of Number of Tubes in Baffle Window"); |
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| 125 | Scd as area (Brief="Shell to Baffle Leakage Area"); |
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| 126 | Std as area (Brief="Tube to Baffle Hole Leakage Area"); |
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| 127 | Rs as Real (Brief="Ratio of the shell to baffle leakage area"); |
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| 128 | Dw as length (Brief="Hydraulic diameter of the baffle window"); |
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| 129 | |
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| 130 | SET |
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| 131 | |
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| 132 | M = PP.MolecularWeight(); |
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| 133 | Pi = 3.14159265; |
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| 134 | |
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| 135 | #"comments" |
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| 136 | Ods = (360/Pi)*acos(1-0.02*Bc); |
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| 137 | |
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| 138 | #"comments" |
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| 139 | Octl = (360/Pi)*acos((Dishell/(Dishell - Lcf - Dotube))*(1-0.02*Bc)); |
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| 140 | |
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| 141 | #"comments" |
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| 142 | Ftw = (Octl/360)-sin(Octl*Pi/180)/(2*Pi); |
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| 143 | |
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| 144 | #"comments" |
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| 145 | Scd = Pi*Dishell*Lcd*((360-Ods)/720); |
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| 146 | |
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| 147 | #"comments" |
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| 148 | Std = Pi*0.25*((Ltd + Dotube)^2-Dotube*Dotube)*Ntt*(1-Ftw); |
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| 149 | |
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| 150 | #"comments" |
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| 151 | Rs = Scd/(Scd+Std); |
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| 152 | |
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| 153 | #"comments" |
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| 154 | Dw = (4*abs((Pi*Dishell*Dishell*((Ods/360)-sin(Ods*Pi/180)/(2*Pi))/4)-(Ntt*Pi*Dotube*Dotube*Ftw/4)))/(Pi*Dotube*Ntt*Ftw+ Pi*Dishell*Ods/360); |
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| 155 | |
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| 156 | #"Tube Side Inlet Nozzle Area" |
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| 157 | Ainozzle_Tube = (Pi*Dinozzle_Tube*Dinozzle_Tube)/4; |
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| 158 | |
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| 159 | #"Tube Side Outlet Nozzle Area" |
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| 160 | Aonozzle_Tube = (Pi*Donozzle_Tube*Donozzle_Tube)/4; |
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| 161 | |
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| 162 | #"Tube Inlet Nozzle Pressure Loss Coeff" |
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| 163 | Kinlet_Tube = 1.1; |
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| 164 | |
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| 165 | #"Tube Outlet Nozzle Pressure Loss Coeff" |
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| 166 | Koutlet_Tube = 0.7; |
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| 167 | |
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| 168 | #"Shell Outlet Nozzle Area" |
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| 169 | Aonozzle_Shell = (Pi*Donozzle_Shell*Donozzle_Shell)/4; |
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| 170 | |
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| 171 | #"Shell Inlet Nozzle Area" |
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| 172 | Ainozzle_Shell = (Pi*Dinozzle_Shell*Dinozzle_Shell)/4; |
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| 173 | |
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| 174 | #"Shell Outlet Escape Area Under Nozzle" |
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| 175 | Aeonozzle_Shell = Pi*Donozzle_Shell*Honozzle_Shell + 0.6*Aonozzle_Shell*(1-(Dotube/pitch)); |
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| 176 | |
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| 177 | #"Shell Inlet Escape Area Under Nozzle" |
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| 178 | Aeinozzle_Shell = Pi*Dinozzle_Shell*Hinozzle_Shell + 0.6*Ainozzle_Shell*(1-(Dotube/pitch)); |
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| 179 | |
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| 180 | EQUATIONS |
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| 181 | |
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| 182 | "Shell Stream Average Temperature" |
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| 183 | Shell.Properties.Average.T = 0.5*InletShell.T + 0.5*OutletShell.T; |
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| 184 | |
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| 185 | "Tube Stream Average Temperature" |
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| 186 | Tubes.Properties.Average.T = 0.5*OutletTube.T + 0.5*OutletTube.T; |
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| 187 | |
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| 188 | "Shell Stream Average Pressure" |
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| 189 | Shell.Properties.Average.P = 0.5*InletShell.P+0.5*OutletShell.P; |
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| 190 | |
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| 191 | "Tube Stream Average Pressure" |
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| 192 | Tubes.Properties.Average.P = 0.5*OutletTube.P+0.5*OutletTube.P; |
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| 193 | |
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| 194 | "Shell Stream Average Molecular Weight" |
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| 195 | Shell.Properties.Average.Mw = sum(M*InletShell.z); |
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| 196 | |
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| 197 | "Tube Stream Average Molecular Weight" |
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| 198 | Tubes.Properties.Average.Mw = sum(M*OutletTube.z); |
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| 199 | |
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| 200 | if InletTube.v equal 0 |
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| 201 | |
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| 202 | then |
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| 203 | |
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| 204 | "Tube Stream Average Heat Capacity" |
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| 205 | Tubes.Properties.Average.Cp = PP.LiquidCp(Tubes.Properties.Average.T,Tubes.Properties.Average.P,OutletTube.z); |
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| 206 | |
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| 207 | "Tube Stream Average Mass Density" |
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| 208 | Tubes.Properties.Average.rho = PP.LiquidDensity(Tubes.Properties.Average.T,Tubes.Properties.Average.P,OutletTube.z); |
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| 209 | |
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| 210 | "Tube Stream Inlet Mass Density" |
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| 211 | Tubes.Properties.Inlet.rho = PP.LiquidDensity(OutletTube.T,OutletTube.P,OutletTube.z); |
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| 212 | |
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| 213 | "Tube Stream Outlet Mass Density" |
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| 214 | Tubes.Properties.Outlet.rho = PP.LiquidDensity(OutletTube.T,OutletTube.P,OutletTube.z); |
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| 215 | |
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| 216 | "TubeStream Average Viscosity" |
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| 217 | Tubes.Properties.Average.Mu = PP.LiquidViscosity(Tubes.Properties.Average.T,Tubes.Properties.Average.P,OutletTube.z); |
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| 218 | |
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| 219 | "Tube Stream Average Conductivity" |
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| 220 | Tubes.Properties.Average.K = PP.LiquidThermalConductivity(Tubes.Properties.Average.T,Tubes.Properties.Average.P,OutletTube.z); |
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| 221 | |
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| 222 | "Tube Stream Viscosity at Wall Temperature" |
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| 223 | Tubes.Properties.Wall.Mu = PP.LiquidViscosity(Tubes.Properties.Wall.Twall,Tubes.Properties.Average.P,OutletTube.z); |
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| 224 | |
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| 225 | else |
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| 226 | |
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| 227 | "Tube Stream Average Heat Capacity" |
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| 228 | Tubes.Properties.Average.Cp = PP.VapourCp(Tubes.Properties.Average.T,Tubes.Properties.Average.P,OutletTube.z); |
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| 229 | |
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| 230 | "Tube Stream Average Mass Density" |
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| 231 | Tubes.Properties.Average.rho = PP.VapourDensity(Tubes.Properties.Average.T,Tubes.Properties.Average.P,OutletTube.z); |
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| 232 | |
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| 233 | "Tube Stream Inlet Mass Density" |
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| 234 | Tubes.Properties.Inlet.rho = PP.VapourDensity(OutletTube.T,OutletTube.P,OutletTube.z); |
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| 235 | |
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| 236 | "Tube Stream Outlet Mass Density" |
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| 237 | Tubes.Properties.Outlet.rho = PP.VapourDensity(OutletTube.T,OutletTube.P,OutletTube.z); |
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| 238 | |
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| 239 | "Tube Stream Average Viscosity " |
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| 240 | Tubes.Properties.Average.Mu = PP.VapourViscosity(Tubes.Properties.Average.T,Tubes.Properties.Average.P,OutletTube.z); |
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| 241 | |
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| 242 | "Tube Stream Average Conductivity " |
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| 243 | Tubes.Properties.Average.K = PP.VapourThermalConductivity(Tubes.Properties.Average.T,Tubes.Properties.Average.P,OutletTube.z); |
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| 244 | |
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| 245 | "Tube Stream Viscosity at Wall Temperature" |
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| 246 | Tubes.Properties.Wall.Mu = PP.VapourViscosity(Tubes.Properties.Wall.Twall,Tubes.Properties.Average.P,OutletTube.z); |
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| 247 | |
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| 248 | end |
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| 249 | |
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| 250 | if InletShell.v equal 0 |
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| 251 | |
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| 252 | then |
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| 253 | |
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| 254 | "Shell Stream Average Heat Capacity" |
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| 255 | Shell.Properties.Average.Cp = PP.LiquidCp(Shell.Properties.Average.T,Shell.Properties.Average.P,InletShell.z); |
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| 256 | |
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| 257 | "Shell Stream Average Mass Density" |
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| 258 | Shell.Properties.Average.rho = PP.LiquidDensity(Shell.Properties.Average.T,Shell.Properties.Average.P,InletShell.z); |
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| 259 | |
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| 260 | "ShellStream Inlet Mass Density" |
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| 261 | Shell.Properties.Inlet.rho = PP.LiquidDensity(InletShell.T,InletShell.P,InletShell.z); |
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| 262 | |
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| 263 | "Shell Stream Outlet Mass Density" |
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| 264 | Shell.Properties.Outlet.rho = PP.LiquidDensity(OutletShell.T,OutletShell.P,OutletShell.z); |
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| 265 | |
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| 266 | "Shell Stream Average Viscosity" |
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| 267 | Shell.Properties.Average.Mu = PP.LiquidViscosity(Shell.Properties.Average.T,Shell.Properties.Average.P,InletShell.z); |
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| 268 | |
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| 269 | "Shell Stream Average Conductivity" |
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| 270 | Shell.Properties.Average.K = PP.LiquidThermalConductivity(Shell.Properties.Average.T,Shell.Properties.Average.P,InletShell.z); |
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| 271 | |
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| 272 | "ShellStream Viscosity at Wall Temperature" |
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| 273 | Shell.Properties.Wall.Mu = PP.LiquidViscosity(Shell.Properties.Wall.Twall,Shell.Properties.Average.P,InletShell.z); |
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| 274 | |
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| 275 | |
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| 276 | else |
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| 277 | |
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| 278 | "Shell Stream Average Heat Capacity" |
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| 279 | Shell.Properties.Average.Cp = PP.VapourCp(Shell.Properties.Average.T,Shell.Properties.Average.P,InletShell.z); |
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| 280 | |
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| 281 | "Shell Stream Average Mass Density" |
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| 282 | Shell.Properties.Average.rho = PP.VapourDensity(Shell.Properties.Average.T,Shell.Properties.Average.P,InletShell.z); |
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| 283 | |
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| 284 | "Shell Stream Inlet Mass Density" |
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| 285 | Shell.Properties.Inlet.rho = PP.VapourDensity(InletShell.T,InletShell.P,InletShell.z); |
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| 286 | |
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| 287 | "Shell Stream Outlet Mass Density" |
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| 288 | Shell.Properties.Outlet.rho = PP.VapourDensity(OutletShell.T,OutletShell.P,OutletShell.z); |
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| 289 | |
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| 290 | "Shell Stream Average Viscosity" |
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| 291 | Shell.Properties.Average.Mu = PP.VapourViscosity(Shell.Properties.Average.T,Shell.Properties.Average.P,InletShell.z); |
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| 292 | |
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| 293 | "Shell Stream Average Conductivity" |
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| 294 | Shell.Properties.Average.K = PP.VapourThermalConductivity(Shell.Properties.Average.T,Shell.Properties.Average.P,InletShell.z); |
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| 295 | |
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| 296 | "Shell Stream Viscosity at Wall Temperature" |
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| 297 | Shell.Properties.Wall.Mu = PP.VapourViscosity(Shell.Properties.Wall.Twall,Shell.Properties.Average.P,InletShell.z); |
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| 298 | |
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| 299 | end |
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| 300 | |
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| 301 | switch Side |
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| 302 | |
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| 303 | case "shell": |
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| 304 | |
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| 305 | "Energy Balance Hot Stream" |
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| 306 | Details.Q = InletShell.F*(InletShell.h-OutletShell.h); |
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| 307 | |
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| 308 | "Energy Balance Cold Stream" |
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| 309 | Details.Q =-InletTube.F*(InletTube.h-OutletTube.h); |
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| 310 | |
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| 311 | when InletTube.T > InletShell.T switchto "tubes"; |
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| 312 | |
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| 313 | case "tubes": |
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| 314 | |
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| 315 | "Energy Balance Hot Stream" |
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| 316 | Details.Q = InletTube.F*(InletTube.h-OutletTube.h); |
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| 317 | |
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| 318 | "Energy Balance Cold Stream" |
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| 319 | Details.Q =-InletShell.F*(InletShell.h-OutletShell.h); |
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| 320 | |
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| 321 | when InletTube.T < InletShell.T switchto "shell"; |
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| 322 | |
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| 323 | end |
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| 324 | |
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| 325 | "Flow Mass Inlet Tube Stream" |
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| 326 | Tubes.Properties.Inlet.Fw = sum(M*InletTube.z)*InletTube.F; |
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| 327 | |
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| 328 | "Flow Mass Outlet Tube Stream" |
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| 329 | Tubes.Properties.Outlet.Fw = sum(M*OutletTube.z)*OutletTube.F; |
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| 330 | |
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| 331 | "Flow Mass Inlet Shell Stream" |
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| 332 | Shell.Properties.Inlet.Fw = sum(M*InletShell.z)*InletShell.F; |
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| 333 | |
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| 334 | "Flow Mass Outlet Shell Stream" |
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| 335 | Shell.Properties.Outlet.Fw = sum(M*OutletShell.z)*OutletShell.F; |
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| 336 | |
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| 337 | "Molar Balance Shell Stream" |
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| 338 | OutletShell.F = InletShell.F; |
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| 339 | |
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| 340 | "Molar Balance Tube Stream" |
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| 341 | OutletTube.F = InletTube.F; |
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| 342 | |
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| 343 | "Shell Stream Molar Fraction Constraint" |
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| 344 | OutletShell.z=InletShell.z; |
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| 345 | |
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| 346 | "Tube Stream Molar Fraction Constraint" |
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| 347 | OutletTube.z=InletTube.z; |
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| 348 | |
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| 349 | "Jc Factor" |
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| 350 | Shell.HeatTransfer.Jc = 0.55+0.72*(1-2*Ftw); |
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| 351 | |
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| 352 | "Jl Factor" |
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| 353 | Shell.HeatTransfer.Jl = 0.44*(1-Rs)+(1-0.44*(1-Rs))*exp(-2.2*(Scd + Std)/Shell.HeatTransfer.Sm); |
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| 354 | |
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| 355 | "Total J Factor" |
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| 356 | Shell.HeatTransfer.Jtotal = Shell.HeatTransfer.Jc*Shell.HeatTransfer.Jl*Shell.HeatTransfer.Jb*Shell.HeatTransfer.Jr*Shell.HeatTransfer.Js; |
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| 357 | |
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| 358 | "Mass Velocity in Window Zone" |
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| 359 | mw = Shell.Properties.Inlet.Fw/sqrt(abs(Shell.HeatTransfer.Sm*abs((Pi*Dishell*Dishell*((Ods/360)-sin(Ods*Pi/180)/(2*Pi))/4)-(Ntt*Pi*Dotube*Dotube*Ftw/4)))); |
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| 360 | |
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| 361 | switch TubeFlowRegime |
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| 362 | |
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| 363 | case "laminar": |
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| 364 | |
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| 365 | "Friction Factor for heat Transfer: Not Necessary in Laminar Correlation - Use any one equation that you want" |
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| 366 | Tubes.HeatTransfer.fi = 16/Tubes.HeatTransfer.Re; |
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| 367 | |
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| 368 | "Friction Factor for Pressure Drop in Laminar Flow" |
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| 369 | Tubes.PressureDrop.fi = 16/Tubes.HeatTransfer.Re; |
---|
| 370 | |
---|
| 371 | switch LaminarCorrelation |
---|
| 372 | |
---|
| 373 | case "Hausen": |
---|
| 374 | |
---|
| 375 | "Nusselt Number in Laminar Flow - Hausen Equation" |
---|
| 376 | Tubes.HeatTransfer.Nu = 3.665 + ((0.19*((Ditube/Ltube)*Tubes.HeatTransfer.Re*Tubes.HeatTransfer.PR)^0.8)/(1+0.117*((Ditube/Ltube)*Tubes.HeatTransfer.Re*Tubes.HeatTransfer.PR)^0.467)); |
---|
| 377 | |
---|
| 378 | case "Schlunder": |
---|
| 379 | |
---|
| 380 | "Nusselt Number in Laminar Flow - Schlunder Equation" |
---|
| 381 | Tubes.HeatTransfer.Nu = (49.027896+4.173281*Tubes.HeatTransfer.Re*Tubes.HeatTransfer.PR*(Ditube/Ltube))^(1/3); |
---|
| 382 | |
---|
| 383 | end |
---|
| 384 | |
---|
| 385 | when Tubes.HeatTransfer.Re > 2300 switchto "transition"; |
---|
| 386 | |
---|
| 387 | case "transition": |
---|
| 388 | |
---|
| 389 | "Friction Factor for heat Transfer : for use in Gnielinski Equation" |
---|
| 390 | Tubes.HeatTransfer.fi = 1/(0.79*ln(Tubes.HeatTransfer.Re)-1.64)^2; |
---|
| 391 | |
---|
| 392 | "Friction Factor for Pressure Drop in Transition Flow" |
---|
| 393 | Tubes.PressureDrop.fi = 0.0122; |
---|
| 394 | |
---|
| 395 | switch TransitionCorrelation |
---|
| 396 | |
---|
| 397 | case "Gnielinski": |
---|
| 398 | |
---|
| 399 | "Nusselt Number in Transition Flow - Gnielinski Equation" |
---|
| 400 | Tubes.HeatTransfer.Nu*(1+(12.7*sqrt(0.125*Tubes.HeatTransfer.fi)*((Tubes.HeatTransfer.PR)^(2/3) -1))) = 0.125*Tubes.HeatTransfer.fi*(Tubes.HeatTransfer.Re-1000)*Tubes.HeatTransfer.PR; |
---|
| 401 | |
---|
| 402 | case "ESDU": |
---|
| 403 | |
---|
| 404 | "Nusselt Number in Transition Flow - ESDU Equation" |
---|
| 405 | Tubes.HeatTransfer.Nu =1;#to be implemented |
---|
| 406 | |
---|
| 407 | end |
---|
| 408 | |
---|
| 409 | when Tubes.HeatTransfer.Re < 2300 switchto "laminar"; |
---|
| 410 | when Tubes.HeatTransfer.Re > 10000 switchto "turbulent"; |
---|
| 411 | |
---|
| 412 | case "turbulent": |
---|
| 413 | |
---|
| 414 | "Friction Factor for heat Transfer : for use in Petukhov Equation" |
---|
| 415 | Tubes.HeatTransfer.fi = 1/(1.82*log(Tubes.HeatTransfer.Re)-1.64)^2; |
---|
| 416 | |
---|
| 417 | "Friction Factor for Pressure Drop in Turbulent Flow" |
---|
| 418 | Tubes.PressureDrop.fi = 0.0035 + 0.264*Tubes.HeatTransfer.Re^(-0.42); |
---|
| 419 | |
---|
| 420 | switch TurbulentCorrelation |
---|
| 421 | |
---|
| 422 | case "Petukhov": |
---|
| 423 | |
---|
| 424 | "Nusselt Number in Turbulent Flow - Petukhov Equation" |
---|
| 425 | Tubes.HeatTransfer.Nu*(1.07+(12.7*sqrt(0.125*Tubes.HeatTransfer.fi)*((Tubes.HeatTransfer.PR)^(2/3) -1))) = 0.125*Tubes.HeatTransfer.fi*Tubes.HeatTransfer.Re*Tubes.HeatTransfer.PR; |
---|
| 426 | |
---|
| 427 | case "SiederTate": |
---|
| 428 | |
---|
| 429 | "Nusselt Number in Transition Flow - Sieder Tate Equation" |
---|
| 430 | Tubes.HeatTransfer.Nu = 0.027*(Tubes.HeatTransfer.PR)^(1/3)*(Tubes.HeatTransfer.Re)^(4/5); |
---|
| 431 | |
---|
| 432 | end |
---|
| 433 | |
---|
| 434 | when Tubes.HeatTransfer.Re < 10000 switchto "transition"; |
---|
| 435 | |
---|
| 436 | end |
---|
| 437 | |
---|
| 438 | switch Pattern |
---|
| 439 | |
---|
| 440 | case "Triangle": |
---|
| 441 | |
---|
| 442 | "Shell Side Cross Flow Area" |
---|
| 443 | Shell.HeatTransfer.Sm= Baffles.Ls*(Lcf+((Dishell-Lcf-Dotube)/pitch)*(pitch-Dotube)); |
---|
| 444 | |
---|
| 445 | "Number of Tube rows Crossed in one Crossflow Section" |
---|
| 446 | Nc = Dishell*(1-0.02*Bc)/(0.866*pitch); |
---|
| 447 | |
---|
| 448 | "Number of Effective Crossflow rows in Each Window" |
---|
| 449 | Ncw = 0.8*(Dishell*0.01*Bc-(Lcf + Dotube)*0.5)/(0.866*pitch); |
---|
| 450 | |
---|
| 451 | "Variable for calculating Ji heat transfer correction Factor" |
---|
| 452 | a = 1.45/(1+0.14*Shell.HeatTransfer.Re^0.519); |
---|
| 453 | |
---|
| 454 | "Variable for calculating Shell Side Pressure Drop Friction Factor" |
---|
| 455 | b=7/(1+0.14*Shell.HeatTransfer.Re^0.5); |
---|
| 456 | |
---|
| 457 | "Correction Factor for Pressure Drop" |
---|
| 458 | Rss = Nss/(Dishell*(1-0.02*Bc)/(0.866*pitch)) ; |
---|
| 459 | |
---|
| 460 | "Ideal Shell Side Pressure Drop" |
---|
| 461 | Shell.PressureDrop.Pideal= 2*Shell.PressureDrop.fi*(Dishell*(1-0.02*Bc)/(0.866*pitch))*(Shell.Properties.Inlet.Fw/Shell.HeatTransfer.Sm)^2/(Shell.Properties.Average.rho*Shell.HeatTransfer.Phi); |
---|
| 462 | |
---|
| 463 | "Shell Pressure End Zones" |
---|
| 464 | Shell.PressureDrop.PdEndZones = Shell.PressureDrop.Pideal*(1+ (Ncw/(Dishell*(1-0.02*Bc)/(0.866*pitch))))*Rb*Rspd; |
---|
| 465 | |
---|
| 466 | switch ShellRange |
---|
| 467 | |
---|
| 468 | case "range1": |
---|
| 469 | |
---|
| 470 | "Ji Factor" |
---|
| 471 | Shell.HeatTransfer.Ji =1.40*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^0.667; |
---|
| 472 | |
---|
| 473 | "Shell Side Pressure Drop Friction Factor" |
---|
| 474 | Shell.PressureDrop.fi=48*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-1; |
---|
| 475 | |
---|
| 476 | when Shell.HeatTransfer.Re > 10 switchto "range2"; |
---|
| 477 | |
---|
| 478 | case "range2": |
---|
| 479 | |
---|
| 480 | "Ji Factor" |
---|
| 481 | Shell.HeatTransfer.Ji =1.36*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^-0.657; |
---|
| 482 | |
---|
| 483 | "Shell Side Pressure Drop Friction Factor" |
---|
| 484 | Shell.PressureDrop.fi=45.10*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-0.973; |
---|
| 485 | |
---|
| 486 | when Shell.HeatTransfer.Re > 100 switchto "range3"; |
---|
| 487 | |
---|
| 488 | case "range3": |
---|
| 489 | |
---|
| 490 | "Ji Factor" |
---|
| 491 | Shell.HeatTransfer.Ji =0.593*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^-0.477; |
---|
| 492 | |
---|
| 493 | "Shell Side Pressure Drop Friction Factor" |
---|
| 494 | Shell.PressureDrop.fi=4.570*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-0.476; |
---|
| 495 | |
---|
| 496 | when Shell.HeatTransfer.Re > 1000 switchto "range4"; |
---|
| 497 | |
---|
| 498 | case "range4": |
---|
| 499 | |
---|
| 500 | "Ji Factor" |
---|
| 501 | Shell.HeatTransfer.Ji =0.321*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^-0.388; |
---|
| 502 | |
---|
| 503 | "Shell Side Pressure Drop Friction Factor" |
---|
| 504 | Shell.PressureDrop.fi=0.486*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-0.152; |
---|
| 505 | |
---|
| 506 | when Shell.HeatTransfer.Re > 10000 switchto "range5"; |
---|
| 507 | |
---|
| 508 | case "range5": |
---|
| 509 | |
---|
| 510 | "Ji Factor" |
---|
| 511 | Shell.HeatTransfer.Ji =0.321*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^-0.388; |
---|
| 512 | |
---|
| 513 | "Shell Side Pressure Drop Friction Factor" |
---|
| 514 | Shell.PressureDrop.fi=0.372*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-0.123; |
---|
| 515 | |
---|
| 516 | when Shell.HeatTransfer.Re < 10000 switchto "range4"; |
---|
| 517 | |
---|
| 518 | end |
---|
| 519 | |
---|
| 520 | case "Rotated Square": |
---|
| 521 | |
---|
| 522 | "Shell Side Cross Flow Area" |
---|
| 523 | Shell.HeatTransfer.Sm= Baffles.Ls*(Lcf+((Dishell-Lcf-Dotube)/(0.707*pitch))*(pitch-Dotube)); |
---|
| 524 | |
---|
| 525 | "Number of Tube rows Crossed in one Crossflow Section" |
---|
| 526 | Nc = Dishell*(1-0.02*Bc)/(0.707*pitch); |
---|
| 527 | |
---|
| 528 | "Number of Effective Crossflow rows in Each Window" |
---|
| 529 | Ncw = 0.8*(Dishell*0.01*Bc-(Lcf + Dotube)*0.5)/(0.707*pitch); |
---|
| 530 | |
---|
| 531 | "Variable for calculating Ji heat transfer correction Factor" |
---|
| 532 | a = 1.930/(1+0.14*Shell.HeatTransfer.Re^0.500); |
---|
| 533 | |
---|
| 534 | "Variable for calculating Shell Side Pressure Drop Friction Factor" |
---|
| 535 | b=6.59/(1+0.14*Shell.HeatTransfer.Re^0.52); |
---|
| 536 | |
---|
| 537 | "Correction Factor for Pressure Drop" |
---|
| 538 | Rss = Nss/(Dishell*(1-0.02*Bc)/(0.707*pitch)) ; |
---|
| 539 | |
---|
| 540 | "Ideal Shell Side Pressure Drop" |
---|
| 541 | Shell.PressureDrop.Pideal= 2*Shell.PressureDrop.fi*(Dishell*(1-0.02*Bc)/(0.707*pitch))*(Shell.Properties.Inlet.Fw/Shell.HeatTransfer.Sm)^2/(Shell.Properties.Average.rho*Shell.HeatTransfer.Phi); |
---|
| 542 | |
---|
| 543 | "Shell Pressure End Zones" |
---|
| 544 | Shell.PressureDrop.PdEndZones = Shell.PressureDrop.Pideal*(1+ (Ncw/(Dishell*(1-0.02*Bc)/(0.707*pitch))))*Rb*Rspd; |
---|
| 545 | |
---|
| 546 | switch ShellRange |
---|
| 547 | |
---|
| 548 | case "range1": |
---|
| 549 | |
---|
| 550 | "Ji Factor" |
---|
| 551 | Shell.HeatTransfer.Ji =1.550*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^0.667; |
---|
| 552 | |
---|
| 553 | "Shell Side Pressure Drop Friction Factor" |
---|
| 554 | Shell.PressureDrop.fi=32*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-1; |
---|
| 555 | |
---|
| 556 | when Shell.HeatTransfer.Re > 10 switchto "range2"; |
---|
| 557 | |
---|
| 558 | case "range2": |
---|
| 559 | |
---|
| 560 | "Ji Factor" |
---|
| 561 | Shell.HeatTransfer.Ji =0.498*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^0.656; |
---|
| 562 | |
---|
| 563 | "Shell Side Pressure Drop Friction Factor" |
---|
| 564 | Shell.PressureDrop.fi=26.20*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-0.913; |
---|
| 565 | |
---|
| 566 | when Shell.HeatTransfer.Re > 100 switchto "range3"; |
---|
| 567 | |
---|
| 568 | case "range3": |
---|
| 569 | |
---|
| 570 | "Ji Factor" |
---|
| 571 | Shell.HeatTransfer.Ji =0.730*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^0.500; |
---|
| 572 | |
---|
| 573 | "Shell Side Pressure Drop Friction Factor" |
---|
| 574 | Shell.PressureDrop.fi=3.50*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-0.476; |
---|
| 575 | |
---|
| 576 | when Shell.HeatTransfer.Re > 1000 switchto "range4"; |
---|
| 577 | |
---|
| 578 | case "range4": |
---|
| 579 | |
---|
| 580 | "Ji Factor" |
---|
| 581 | Shell.HeatTransfer.Ji =0.370*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^-0.396; |
---|
| 582 | |
---|
| 583 | "Shell Side Pressure Drop Friction Factor" |
---|
| 584 | Shell.PressureDrop.fi=0.333*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-0.136; |
---|
| 585 | |
---|
| 586 | when Shell.HeatTransfer.Re > 10000 switchto "range5"; |
---|
| 587 | |
---|
| 588 | case "range5": |
---|
| 589 | |
---|
| 590 | "Ji Factor" |
---|
| 591 | Shell.HeatTransfer.Ji =0.370*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^-0.396; |
---|
| 592 | |
---|
| 593 | "Shell Side Pressure Drop Friction Factor" |
---|
| 594 | Shell.PressureDrop.fi=0.303*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-0.126; |
---|
| 595 | |
---|
| 596 | when Shell.HeatTransfer.Re < 10000 switchto "range4"; |
---|
| 597 | |
---|
| 598 | end |
---|
| 599 | |
---|
| 600 | case "Square": |
---|
| 601 | |
---|
| 602 | "Shell Side Cross Flow Area" |
---|
| 603 | Shell.HeatTransfer.Sm= Baffles.Ls*(Lcf+((Dishell-Lcf-Dotube)/pitch)*(pitch-Dotube)); |
---|
| 604 | |
---|
| 605 | "Number of Tube rows Crossed in one Crossflow Section" |
---|
| 606 | Nc = Dishell*(1-0.02*Bc)/pitch; |
---|
| 607 | |
---|
| 608 | "Number of Effective Crossflow rows in Each Window" |
---|
| 609 | Ncw = 0.8*(Dishell*0.01*Bc-(Lcf + Dotube)*0.5)/pitch; |
---|
| 610 | |
---|
| 611 | "Variable for calculating Ji heat transfer correction Factor" |
---|
| 612 | a = 1.187/(1+0.14*Shell.HeatTransfer.Re^0.370); |
---|
| 613 | |
---|
| 614 | "Variable for calculating Shell Side Pressure Drop Friction Factor" |
---|
| 615 | b=6.30/(1+0.14*Shell.HeatTransfer.Re^0.38); |
---|
| 616 | |
---|
| 617 | "Correction Factor for Pressure Drop" |
---|
| 618 | Rss = Nss/(Dishell*(1-0.02*Bc)/pitch) ; |
---|
| 619 | |
---|
| 620 | "Ideal Shell Side Pressure Drop" |
---|
| 621 | Shell.PressureDrop.Pideal= 2*Shell.PressureDrop.fi*(Dishell*(1-0.02*Bc)/pitch)*(Shell.Properties.Inlet.Fw/Shell.HeatTransfer.Sm)^2/(Shell.Properties.Average.rho*Shell.HeatTransfer.Phi); |
---|
| 622 | |
---|
| 623 | "Shell Pressure End Zones" |
---|
| 624 | Shell.PressureDrop.PdEndZones = Shell.PressureDrop.Pideal*(1+ (Ncw/(Dishell*(1-0.02*Bc)/pitch)))*Rb*Rspd; |
---|
| 625 | |
---|
| 626 | switch ShellRange |
---|
| 627 | |
---|
| 628 | case "range1": |
---|
| 629 | |
---|
| 630 | "Ji Factor" |
---|
| 631 | Shell.HeatTransfer.Ji =0.970*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^-0.667; |
---|
| 632 | |
---|
| 633 | "Shell Side Pressure Drop Friction Factor" |
---|
| 634 | Shell.PressureDrop.fi=35*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-1; |
---|
| 635 | |
---|
| 636 | when Shell.HeatTransfer.Re > 10 switchto "range2"; |
---|
| 637 | |
---|
| 638 | case "range2": |
---|
| 639 | |
---|
| 640 | "Ji Factor" |
---|
| 641 | Shell.HeatTransfer.Ji =0.900*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^-0.631; |
---|
| 642 | |
---|
| 643 | "Shell Side Pressure Drop Friction Factor" |
---|
| 644 | Shell.PressureDrop.fi=32.10*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-0.963; |
---|
| 645 | |
---|
| 646 | when Shell.HeatTransfer.Re > 100 switchto "range3"; |
---|
| 647 | |
---|
| 648 | case "range3": |
---|
| 649 | |
---|
| 650 | "Ji Factor" |
---|
| 651 | Shell.HeatTransfer.Ji =0.408*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^-0.460; |
---|
| 652 | |
---|
| 653 | "Shell Side Pressure Drop Friction Factor" |
---|
| 654 | Shell.PressureDrop.fi=6.090*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-0.602; |
---|
| 655 | |
---|
| 656 | when Shell.HeatTransfer.Re > 1000 switchto "range4"; |
---|
| 657 | |
---|
| 658 | case "range4": |
---|
| 659 | |
---|
| 660 | "Ji Factor" |
---|
| 661 | Shell.HeatTransfer.Ji =0.107*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^-0.266; |
---|
| 662 | |
---|
| 663 | "Shell Side Pressure Drop Friction Factor" |
---|
| 664 | Shell.PressureDrop.fi=0.0815*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^0.022; |
---|
| 665 | |
---|
| 666 | when Shell.HeatTransfer.Re > 10000 switchto "range5"; |
---|
| 667 | |
---|
| 668 | case "range5": |
---|
| 669 | |
---|
| 670 | "Ji Factor" |
---|
| 671 | Shell.HeatTransfer.Ji =0.370*((1.33*Dotube/pitch)^a)*Shell.HeatTransfer.Re^-0.395; |
---|
| 672 | |
---|
| 673 | "Shell Side Pressure Drop Friction Factor" |
---|
| 674 | Shell.PressureDrop.fi=0.391*((1.33*Dotube/pitch)^b)*Shell.HeatTransfer.Re^-0.148; |
---|
| 675 | |
---|
| 676 | when Shell.HeatTransfer.Re < 10000 switchto "range4"; |
---|
| 677 | |
---|
| 678 | end |
---|
| 679 | |
---|
| 680 | end |
---|
| 681 | |
---|
| 682 | switch ShellFlowRegime |
---|
| 683 | |
---|
| 684 | case "deep laminar": |
---|
| 685 | |
---|
| 686 | "Jr Factor" |
---|
| 687 | Shell.HeatTransfer.Jr = (10/((Nc +Ncw)*(Nb+1)))^0.18; |
---|
| 688 | |
---|
| 689 | "Js Factor" |
---|
| 690 | Shell.HeatTransfer.Js = (Nb-1+(Baffles.Lsi/Baffles.Ls)^0.7 + (Baffles.Lso/Baffles.Ls)^0.7)/(Nb-1+(Baffles.Lsi/Baffles.Ls) + (Baffles.Lso/Baffles.Ls)); |
---|
| 691 | |
---|
| 692 | "Jb Factor" |
---|
| 693 | Shell.HeatTransfer.Jb = exp(-1.35*( Lcf+ Dotube)*Baffles.Ls/Shell.HeatTransfer.Sm*(1-(2*(Nss/Nc)^(1/3)))); |
---|
| 694 | |
---|
| 695 | "ByPass Correction Factor for Pressure Drop" |
---|
| 696 | Rb = exp(-4.7*((Lcf + Dotube)*Baffles.Ls/Shell.HeatTransfer.Sm)*(1-(2*Rss)^(1/3))); |
---|
| 697 | |
---|
| 698 | "Pressure Drop Correction Factor for Unequal Baffle Spacing" |
---|
| 699 | Rspd = (Baffles.Ls/Baffles.Lso) + (Baffles.Ls/Baffles.Lsi); |
---|
| 700 | |
---|
| 701 | "Shell Pressure Drop Baffle Window" |
---|
| 702 | Shell.PressureDrop.Pdwindow = Nb*((26/Shell.Properties.Average.rho)*mw*Shell.Properties.Average.Mu*(Ncw/(pitch-Dotube)+ Baffles.Ls/(Dw*Dw))+ 0.5*mw*mw/Shell.Properties.Average.rho)*exp(-1.33*(1+Rs)*((Scd + Std)/Shell.HeatTransfer.Sm)^(-0.15*(1+Rs) + 0.8)); |
---|
| 703 | |
---|
| 704 | when Shell.HeatTransfer.Re > 20 switchto "laminar"; |
---|
| 705 | |
---|
| 706 | case "laminar": |
---|
| 707 | |
---|
| 708 | "Jr Factor" |
---|
| 709 | Shell.HeatTransfer.Jr = (10/((Nc +Ncw)*(Nb+1)))^0.18 + (0.25-0.0125*Shell.HeatTransfer.Re)*((10/((Nc +Ncw)*(Nb+1)))^0.18 - 1); |
---|
| 710 | |
---|
| 711 | "Js Factor" |
---|
| 712 | Shell.HeatTransfer.Js = (Nb-1+(Baffles.Lsi/Baffles.Ls)^0.7 + (Baffles.Lso/Baffles.Ls)^0.7)/(Nb-1+(Baffles.Lsi/Baffles.Ls) + (Baffles.Lso/Baffles.Ls)); |
---|
| 713 | |
---|
| 714 | "Jb Factor" |
---|
| 715 | Shell.HeatTransfer.Jb = exp(-1.35*( Lcf+ Dotube)*Baffles.Ls/Shell.HeatTransfer.Sm*(1-(2*(Nss/Nc)^(1/3)))); |
---|
| 716 | |
---|
| 717 | "ByPass Correction Factor for Pressure Drop" |
---|
| 718 | Rb = exp(-4.7*((Lcf + Dotube)*Baffles.Ls/Shell.HeatTransfer.Sm)*(1-(2*Rss)^(1/3))); |
---|
| 719 | |
---|
| 720 | "Pressure Drop Correction Factor for Unequal Baffle Spacing" |
---|
| 721 | Rspd = (Baffles.Ls/Baffles.Lso) + (Baffles.Ls/Baffles.Lsi); |
---|
| 722 | |
---|
| 723 | "Shell Pressure Drop Baffle Window" |
---|
| 724 | Shell.PressureDrop.Pdwindow = Nb*((26/Shell.Properties.Average.rho)*mw*Shell.Properties.Average.Mu*(Ncw/(pitch-Dotube)+ Baffles.Ls/(Dw*Dw))+ 0.5*mw*mw/Shell.Properties.Average.rho)*exp(-1.33*(1+Rs)*((Scd + Std)/Shell.HeatTransfer.Sm)^(-0.15*(1+Rs) + 0.8)); |
---|
| 725 | |
---|
| 726 | when Shell.HeatTransfer.Re < 20 switchto "deep laminar"; |
---|
| 727 | when Shell.HeatTransfer.Re > 100 switchto "turbulent"; |
---|
| 728 | |
---|
| 729 | case "turbulent": |
---|
| 730 | |
---|
| 731 | "Jr Factor" |
---|
| 732 | Shell.HeatTransfer.Jr = 1; |
---|
| 733 | |
---|
| 734 | "Js Factor" |
---|
| 735 | Shell.HeatTransfer.Js = (Nb-1+(Baffles.Lsi/Baffles.Ls)^0.4 + (Baffles.Lso/Baffles.Ls)^0.4)/(Nb-1+(Baffles.Lsi/Baffles.Ls) + (Baffles.Lso/Baffles.Ls)); |
---|
| 736 | |
---|
| 737 | "Jb Factor" |
---|
| 738 | Shell.HeatTransfer.Jb = exp(-1.25*( Lcf+ Dotube)*Baffles.Ls/Shell.HeatTransfer.Sm*(1-(2*(Nss/Nc)^(1/3)))); |
---|
| 739 | |
---|
| 740 | "ByPass Correction Factor for Pressure Drop" |
---|
| 741 | Rb = exp(-3.7*((Lcf + Dotube)*Baffles.Ls/Shell.HeatTransfer.Sm)*(1-(2*Rss)^(1/3))); |
---|
| 742 | |
---|
| 743 | "Pressure Drop Correction Factor for Unequal Baffle Spacing" |
---|
| 744 | Rspd = (Baffles.Ls/Baffles.Lso)^1.8 + (Baffles.Ls/Baffles.Lsi)^1.8; |
---|
| 745 | |
---|
| 746 | "Shell Pressure Drop Baffle Window" |
---|
| 747 | Shell.PressureDrop.Pdwindow = Nb*((2+0.6*Ncw)*0.5*mw*mw/Shell.Properties.Average.rho)*exp(-1.33*(1+Rs)*((Scd + Std)/Shell.HeatTransfer.Sm)^(-0.15*(1+Rs) + 0.8)); |
---|
| 748 | |
---|
| 749 | when Shell.HeatTransfer.Re < 100 switchto "laminar"; |
---|
| 750 | |
---|
| 751 | end |
---|
| 752 | |
---|
| 753 | "Shell Pressure Drop Cross Flow" |
---|
| 754 | Shell.PressureDrop.PdCross = Shell.PressureDrop.Pideal*Rb*(Nb-1)*exp(-1.33*(1+Rs)*((Scd + Std)/Shell.HeatTransfer.Sm)^(-0.15*(1+Rs) + 0.8)); |
---|
| 755 | |
---|
| 756 | "Shell Side Phi correction" |
---|
| 757 | Shell.HeatTransfer.Phi = (Shell.Properties.Average.Mu/Shell.Properties.Wall.Mu)^0.14; |
---|
| 758 | |
---|
| 759 | "Tube Side Phi correction" |
---|
| 760 | Tubes.HeatTransfer.Phi = (Tubes.Properties.Average.Mu/Tubes.Properties.Wall.Mu)^0.14; |
---|
| 761 | |
---|
| 762 | "Shell Side inlet Nozzle rho-V^2" |
---|
| 763 | Shell.PressureDrop.RVsquare_in = Shell.Properties.Inlet.rho*(Shell.PressureDrop.Vnozzle_in)^2; |
---|
| 764 | |
---|
| 765 | "Shell Side Outlet Nozzle rho-V^2" |
---|
| 766 | Shell.PressureDrop.RVsquare_out = Shell.Properties.Outlet.rho*(Shell.PressureDrop.Vnozzle_out)^2; |
---|
| 767 | |
---|
| 768 | "Tube Side Pressure Drop" |
---|
| 769 | Tubes.PressureDrop.PdTube = 2*Tubes.PressureDrop.fi*Ltube*Tubes.Properties.Average.rho*(Tubes.HeatTransfer.Vtube^2)*Tpass/(Ditube*Tubes.HeatTransfer.Phi); |
---|
| 770 | |
---|
| 771 | "Pressure Drop Tube Side Inlet Nozzle" |
---|
| 772 | Tubes.PressureDrop.Pdnozzle_in = 0.5*Kinlet_Tube*Tubes.Properties.Inlet.rho*Tubes.PressureDrop.Vnozzle_in^2; |
---|
| 773 | |
---|
| 774 | "Velocity Tube Side Inlet Nozzle" |
---|
| 775 | Tubes.PressureDrop.Vnozzle_in = Tubes.Properties.Inlet.Fw/(Tubes.Properties.Inlet.rho*Ainozzle_Tube); |
---|
| 776 | |
---|
| 777 | "Pressure Drop Tube Side Outlet Nozzle" |
---|
| 778 | Tubes.PressureDrop.Pdnozzle_out = 0.5*Koutlet_Tube*Tubes.Properties.Outlet.rho*Tubes.PressureDrop.Vnozzle_out^2; |
---|
| 779 | |
---|
| 780 | "Velocity Tube Side Outlet Nozzle" |
---|
| 781 | Tubes.PressureDrop.Vnozzle_out = Tubes.Properties.Inlet.Fw/(Tubes.Properties.Outlet.rho*Aonozzle_Tube); |
---|
| 782 | |
---|
| 783 | "Shell Pressure Drop Inlet Nozzle" |
---|
| 784 | Shell.PressureDrop.Pdnozzle_in = (0.5*Shell.Properties.Inlet.Fw^2/Shell.Properties.Inlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); |
---|
| 785 | |
---|
| 786 | "Velocity Shell Side Inlet Nozzle" |
---|
| 787 | Shell.PressureDrop.Vnozzle_in = Shell.Properties.Inlet.Fw/(Shell.Properties.Inlet.rho*Ainozzle_Shell); |
---|
| 788 | |
---|
| 789 | "Shell Pressure Drop Outlet Nozzle" |
---|
| 790 | Shell.PressureDrop.Pdnozzle_out = (0.5*Shell.Properties.Outlet.Fw^2/Shell.Properties.Outlet.rho)*((1/Ainozzle_Shell^2)+(1/Aeinozzle_Shell^2)); |
---|
| 791 | |
---|
| 792 | "Velocity Shell Side Outlet Nozzle" |
---|
| 793 | Shell.PressureDrop.Vnozzle_out = Shell.Properties.Outlet.Fw/(Shell.Properties.Outlet.rho*Aonozzle_Shell); |
---|
| 794 | |
---|
| 795 | "Pressure Drop Shell Stream" |
---|
| 796 | OutletShell.P = InletShell.P - Shell.PressureDrop.Pdtotal; |
---|
| 797 | |
---|
| 798 | "Pressure Drop Tube Stream" |
---|
| 799 | OutletTube.P = InletTube.P - Tubes.PressureDrop.Pdtotal; |
---|
| 800 | |
---|
| 801 | "Shell Wall Temperature" |
---|
| 802 | Shell.Properties.Wall.Twall = (Shell.Properties.Average.T+Tubes.Properties.Average.T)/2; |
---|
| 803 | |
---|
| 804 | "Tube Wall Temperature" |
---|
| 805 | Tubes.Properties.Wall.Twall = (Shell.Properties.Average.T+Tubes.Properties.Average.T)/2; |
---|
| 806 | |
---|
| 807 | "Tube Side Velocity" |
---|
| 808 | Tubes.HeatTransfer.Vtube = Tubes.Properties.Inlet.Fw*Tpass/((Pi*Ditube*Ditube/4)*Tubes.Properties.Average.rho*Ntt); |
---|
| 809 | |
---|
| 810 | "Tube Side Reynolds Number" |
---|
| 811 | Tubes.HeatTransfer.Re = (Tubes.Properties.Average.rho*Tubes.HeatTransfer.Vtube*Ditube)/Tubes.Properties.Average.Mu; |
---|
| 812 | |
---|
| 813 | "Tube Side Prandtl Number" |
---|
| 814 | Tubes.HeatTransfer.PR = ((Tubes.Properties.Average.Cp/Tubes.Properties.Average.Mw)*Tubes.Properties.Average.Mu)/Tubes.Properties.Average.K; |
---|
| 815 | |
---|
| 816 | "Tube Side Film Coefficient" |
---|
| 817 | Tubes.HeatTransfer.htube= (Tubes.HeatTransfer.Nu*Tubes.Properties.Average.K/Ditube)*Tubes.HeatTransfer.Phi; |
---|
| 818 | |
---|
| 819 | "Shell Side Prandtl Number" |
---|
| 820 | Shell.HeatTransfer.PR = ((Shell.Properties.Average.Cp/Shell.Properties.Average.Mw)*Shell.Properties.Average.Mu)/Shell.Properties.Average.K; |
---|
| 821 | |
---|
| 822 | "Overall Heat Transfer Coefficient Dirty" |
---|
| 823 | Details.Ud=1/(Dotube/(Tubes.HeatTransfer.htube*Ditube)+Rfo+Rfi*(Dotube/Ditube)+(Dotube*ln(Dotube/Ditube)/(2*Kwall))+(1/(Shell.HeatTransfer.hshell))); |
---|
| 824 | |
---|
| 825 | "Overall Heat Transfer Coefficient Clean" |
---|
| 826 | Details.Uc=1/(Dotube/(Tubes.HeatTransfer.htube*Ditube)+(Dotube*ln(Dotube/Ditube)/(2*Kwall))+(1/(Shell.HeatTransfer.hshell))); |
---|
| 827 | |
---|
| 828 | "Exchange Surface Area" |
---|
| 829 | Details.A=Pi*Dotube*Ntt*Ltube; |
---|
| 830 | |
---|
| 831 | "Baffles Spacing" |
---|
| 832 | Ltube = Baffles.Lsi+Baffles.Lso+Baffles.Ls*(Nb-1); |
---|
| 833 | |
---|
| 834 | "Shell Side Reynolds Number" |
---|
| 835 | Shell.HeatTransfer.Re = (Dotube*Shell.Properties.Inlet.Fw/Shell.HeatTransfer.Sm)/Shell.Properties.Average.Mu; |
---|
| 836 | |
---|
| 837 | "Shell Heat Transfer Coefficient" |
---|
| 838 | Shell.HeatTransfer.hshell = Shell.HeatTransfer.Ji*(Shell.Properties.Average.Cp/Shell.Properties.Average.Mw)*(Shell.Properties.Inlet.Fw/Shell.HeatTransfer.Sm)*(Shell.HeatTransfer.PR^(-2/3))*Shell.HeatTransfer.Jtotal*Shell.HeatTransfer.Phi; |
---|
| 839 | |
---|
| 840 | end |
---|
| 841 | |
---|
| 842 | Model ShellandTubes_NTU as ShellandTubesBasic |
---|
| 843 | |
---|
| 844 | ATTRIBUTES |
---|
| 845 | Pallete = true; |
---|
| 846 | Icon = "icon/ShellandTubes_NTU"; |
---|
| 847 | Brief = "Shell and Tubes Heat Exchangers"; |
---|
| 848 | Info = |
---|
| 849 | "to be documented"; |
---|
| 850 | |
---|
| 851 | VARIABLES |
---|
| 852 | |
---|
| 853 | Method as NTU_Basic (Brief="NTU Method"); |
---|
| 854 | |
---|
| 855 | EQUATIONS |
---|
| 856 | |
---|
| 857 | "Number of Units Transference" |
---|
| 858 | Method.NTU*Method.Cmin = Details.Ud*Pi*Dotube*Ntt*Ltube; |
---|
| 859 | |
---|
| 860 | "Minimum Heat Capacity" |
---|
| 861 | Method.Cmin = min([Method.Ch,Method.Cc]); |
---|
| 862 | |
---|
| 863 | "Maximum Heat Capacity" |
---|
| 864 | Method.Cmax = max([Method.Ch,Method.Cc]); |
---|
| 865 | |
---|
| 866 | "Thermal Capacity Ratio" |
---|
| 867 | Method.Cr = Method.Cmin/Method.Cmax; |
---|
| 868 | |
---|
| 869 | switch HotSide |
---|
| 870 | |
---|
| 871 | case "shell": |
---|
| 872 | |
---|
| 873 | "Duty" |
---|
| 874 | Details.Q = Method.Eft*Method.Cmin*(InletShell.T-InletTube.T); |
---|
| 875 | |
---|
| 876 | "Hot Stream Heat Capacity" |
---|
| 877 | Method.Ch = InletShell.F*Shell.Properties.Average.Cp; |
---|
| 878 | |
---|
| 879 | "Cold Stream Heat Capacity" |
---|
| 880 | Method.Cc = InletTube.F*Tubes.Properties.Average.Cp; |
---|
| 881 | |
---|
| 882 | when InletTube.T > InletShell.T switchto "tubes"; |
---|
| 883 | |
---|
| 884 | case "tubes": |
---|
| 885 | |
---|
| 886 | "Duty" |
---|
| 887 | Details.Q = Method.Eft*Method.Cmin*(InletTube.T-InletShell.T); |
---|
| 888 | |
---|
| 889 | "Hot Stream Heat Capacity" |
---|
| 890 | Method.Cc = InletShell.F*Shell.Properties.Average.Cp; |
---|
| 891 | |
---|
| 892 | "Cold Stream Heat Capacity" |
---|
| 893 | Method.Ch = InletTube.F*Tubes.Properties.Average.Cp; |
---|
| 894 | |
---|
| 895 | when InletTube.T < InletShell.T switchto "shell"; |
---|
| 896 | |
---|
| 897 | end |
---|
| 898 | |
---|
| 899 | switch ShellType |
---|
| 900 | |
---|
| 901 | case "Fshell": |
---|
| 902 | |
---|
| 903 | "Effectiveness Correction for 2 pass shell side" |
---|
| 904 | Method.Eft1 = 2*(1+Method.Cr+sqrt(1+Method.Cr^2)*((1+exp(-Method.NTU*sqrt(1+Method.Cr^2)))/(1-exp(-Method.NTU*sqrt(1+Method.Cr^2)))) )^-1; |
---|
| 905 | |
---|
| 906 | "TEMA F Shell Effectiveness" |
---|
| 907 | Method.Eft = ( ((1-Method.Eft1*Method.Cr)/(1-Method.Eft1))^2 -1 )*( ((1-Method.Eft1*Method.Cr)/(1-Method.Eft1))^2 - Method.Cr )^-1; |
---|
| 908 | |
---|
| 909 | case "Eshell": |
---|
| 910 | |
---|
| 911 | "TEMA E Shell Effectiveness" |
---|
| 912 | Method.Eft = 2*(1+Method.Cr+sqrt(1+Method.Cr^2)*((1+exp(-Method.NTU*sqrt(1+Method.Cr^2)))/(1-exp(-Method.NTU*sqrt(1+Method.Cr^2)))) )^-1; |
---|
| 913 | # Method.Eft = 1; |
---|
| 914 | |
---|
| 915 | "Variable not in use when 1 Pass Shell Side" |
---|
| 916 | Method.Eft1 = 1; |
---|
| 917 | |
---|
| 918 | end |
---|
| 919 | |
---|
| 920 | end |
---|
| 921 | |
---|
| 922 | Model ShellandTubes_LMTD as ShellandTubesBasic |
---|
| 923 | |
---|
| 924 | ATTRIBUTES |
---|
| 925 | Pallete = true; |
---|
| 926 | Icon = "icon/ShellandTubes_LMTD"; |
---|
| 927 | Brief = "Shell and Tubes Heat Exchangers"; |
---|
| 928 | Info = |
---|
| 929 | "to be documented."; |
---|
| 930 | |
---|
| 931 | PARAMETERS |
---|
| 932 | |
---|
| 933 | LMTDcorrection as Switcher (Brief="LMTD Correction Factor Model",Valid=["Bowmann","Fakeri"],Default="Bowmann"); |
---|
| 934 | |
---|
| 935 | VARIABLES |
---|
| 936 | |
---|
| 937 | Method as LMTD_Basic; |
---|
| 938 | R as positive (Brief=" Capacity Ratio for LMTD Correction Fator",Lower=1e-6); |
---|
| 939 | P as positive (Brief="Non - Dimensional Variable for LMTD Correction Fator ",Lower=1e-6); |
---|
| 940 | Pc as positive (Brief="Non - Dimensional Variable for LMTD Correction Fator when 2 Pass Shell Side",Lower=1e-6); |
---|
| 941 | Rho as positive (Brief="Non - Dimensional Variable for LMTD Correction Fator in Fakeri Equation",Lower=1e-6); |
---|
| 942 | Phi as positive (Brief="Non - Dimensional Variable for LMTD Correction Fator in Fakeri Equation",Lower=1e-6); |
---|
| 943 | lambdaN as positive (Brief="Non - Dimensional Variable for LMTD Correction Fator in Fakeri Equation when 2 Pass Shell Side",Lower=1e-6); |
---|
| 944 | lambda1 as positive (Brief="Non - Dimensional Variable for LMTD Correction Fator in Fakeri Equationwhen 2 Pass Shell Side",Lower=1e-6); |
---|
| 945 | |
---|
| 946 | EQUATIONS |
---|
| 947 | |
---|
| 948 | "Exchange Surface Area" |
---|
| 949 | Details.Q = Details.Ud*Pi*Dotube*Ntt*Ltube*Method.LMTD*Method.Fc; |
---|
| 950 | |
---|
| 951 | switch HotSide |
---|
| 952 | |
---|
| 953 | case "shell": |
---|
| 954 | |
---|
| 955 | "Non Dimensional Variable for LMTD Correction Fator in Fakeri Equation " |
---|
| 956 | Phi*(2*((InletShell.T+ OutletShell.T)-(InletTube.T+ OutletTube.T))) = (sqrt(((InletShell.T- OutletShell.T)*(InletShell.T- OutletShell.T))+((OutletTube.T - InletTube.T)*(OutletTube.T - InletTube.T)))); |
---|
| 957 | |
---|
| 958 | "R: Capacity Ratio for LMTD Correction Fator" |
---|
| 959 | R*(OutletTube.T - InletTube.T ) = (InletShell.T-OutletShell.T); |
---|
| 960 | |
---|
| 961 | "P: Non - Dimensional Variable for LMTD Correction Fator" |
---|
| 962 | P*(InletShell.T- InletTube.T)= (OutletTube.T-InletTube.T); |
---|
| 963 | |
---|
| 964 | "Temperature Difference at Inlet" |
---|
| 965 | Method.DT0 = InletShell.T - OutletTube.T; |
---|
| 966 | |
---|
| 967 | "Temperature Difference at Outlet" |
---|
| 968 | Method.DTL = OutletShell.T - InletTube.T; |
---|
| 969 | |
---|
| 970 | when InletTube.T > InletShell.T switchto "tubes"; |
---|
| 971 | |
---|
| 972 | case "tubes": |
---|
| 973 | |
---|
| 974 | "Non Dimensional Variable for LMTD Correction Fator in Fakeri Equation " |
---|
| 975 | Phi*(2*((InletShell.T+ OutletShell.T)-(InletTube.T+ OutletTube.T))) = (sqrt(((InletShell.T- OutletShell.T)*(InletShell.T- OutletShell.T))+((OutletTube.T - InletTube.T)*(OutletTube.T - InletTube.T)))); |
---|
| 976 | |
---|
| 977 | "R: Capacity Ratio for LMTD Correction Fator" |
---|
| 978 | R*(OutletShell.T - InletShell.T ) = (InletTube.T-OutletTube.T); |
---|
| 979 | |
---|
| 980 | "P: Non - Dimensional Variable for LMTD Correction Fator" |
---|
| 981 | P*(InletTube.T- InletShell.T)= (OutletShell.T-InletShell.T); |
---|
| 982 | |
---|
| 983 | "Temperature Difference at Inlet" |
---|
| 984 | Method.DT0 = InletTube.T - OutletShell.T; |
---|
| 985 | |
---|
| 986 | "Temperature Difference at Outlet" |
---|
| 987 | Method.DTL = OutletTube.T - InletShell.T; |
---|
| 988 | |
---|
| 989 | |
---|
| 990 | when InletTube.T < InletShell.T switchto "shell"; |
---|
| 991 | |
---|
| 992 | end |
---|
| 993 | |
---|
| 994 | switch ShellType |
---|
| 995 | |
---|
| 996 | case "Fshell": |
---|
| 997 | |
---|
| 998 | switch LMTDcorrection |
---|
| 999 | |
---|
| 1000 | case "Bowmann": |
---|
| 1001 | |
---|
| 1002 | " Variable not in use with Bowmann equation" |
---|
| 1003 | lambdaN =1; |
---|
| 1004 | |
---|
| 1005 | " Variable not in use with Bowmann equation" |
---|
| 1006 | lambda1 =1; |
---|
| 1007 | |
---|
| 1008 | #" Variable not in use with Bowmann equation" |
---|
| 1009 | # Phi = 1; |
---|
| 1010 | |
---|
| 1011 | " Variable not in use with Bowmann equation" |
---|
| 1012 | Rho =1; |
---|
| 1013 | |
---|
| 1014 | if R equal 1 |
---|
| 1015 | |
---|
| 1016 | then |
---|
| 1017 | |
---|
| 1018 | "Non Dimensional Variable for LMTD Correction Fator when 2 Pass Shell Side" |
---|
| 1019 | Pc*(2-P)= P; |
---|
| 1020 | |
---|
| 1021 | "LMTD Correction Fator when 2 Pass Shell Side" |
---|
| 1022 | Method.Fc= (sqrt(2)*Pc)/((1-Pc)*ln( abs( ( 2-Pc*0.585786)/( 2-Pc*3.414214)))); |
---|
| 1023 | |
---|
| 1024 | else |
---|
| 1025 | |
---|
| 1026 | "Non Dimensional Variable for LMTD Correction Fator when 2 Pass Shell Side" |
---|
| 1027 | Pc = (sqrt(abs(( 1-P*R)/(1-P)))-1)/(sqrt(abs(( 1-P*R)/(1-P)))-R); |
---|
| 1028 | |
---|
| 1029 | "LMTD Correction Fator when 2 Pass Shell Side" |
---|
| 1030 | Method.Fc = sqrt(R*R+1)*ln(abs((1-Pc*R)/(1-Pc)))/((1-R)*ln( abs( ( 2-Pc*(R+1-sqrt(R*R+1)))/ ( 2-Pc*(R + 1 + sqrt(R*R+1)))))); |
---|
| 1031 | |
---|
| 1032 | end |
---|
| 1033 | |
---|
| 1034 | case "Fakeri": |
---|
| 1035 | |
---|
| 1036 | " Variable not in use with Fakeri equation" |
---|
| 1037 | Pc = P; |
---|
| 1038 | |
---|
| 1039 | "Non Dimensional Variable for LMTD Correction Fator in Fakeri Equation" |
---|
| 1040 | Rho*(1-P*R) = (1-P); |
---|
| 1041 | |
---|
| 1042 | #"Non Dimensional Variable for LMTD Correction Fator in Fakeri Equation " |
---|
| 1043 | # Phi = (sqrt(((Inlet.Hot.T - Outlet.Hot.T)*(Inlet.Hot.T- Outlet.Hot.T))+((Outlet.Cold.T - Inlet.Cold.T)*(Outlet.Cold.T - Inlet.Cold.T))))/(2*((Inlet.Hot.T + Outlet.Hot.T)-( Inlet.Cold.T + Outlet.Cold.T))); |
---|
| 1044 | |
---|
| 1045 | if Rho equal 1 |
---|
| 1046 | |
---|
| 1047 | then |
---|
| 1048 | |
---|
| 1049 | " Variable not in use when Rho = 1" |
---|
| 1050 | lambdaN = 1; |
---|
| 1051 | |
---|
| 1052 | " Variable not in use when Rho = 1" |
---|
| 1053 | lambda1 = 1; |
---|
| 1054 | |
---|
| 1055 | "LMTD Correction Fator when 2 Pass Shell Side" |
---|
| 1056 | Method.Fc = (2*Phi )/(ln(abs((1+Phi )/(1-Phi )))); |
---|
| 1057 | |
---|
| 1058 | else |
---|
| 1059 | |
---|
| 1060 | "Non Dimensional Variable for LMTD Correction Fator in Fakeri Equation" |
---|
| 1061 | lambdaN = (1/ln(sqrt(abs(Rho))))*((2*sqrt(abs(Rho))-2)/(sqrt(abs(Rho))+1)); |
---|
| 1062 | |
---|
| 1063 | "Non Dimensional Variable for LMTD Correction Fator in Fakeri Equation" |
---|
| 1064 | lambda1 = (1/ln(abs(Rho)))*((2*Rho-2)/(Rho+1)); |
---|
| 1065 | |
---|
| 1066 | "LMTD Correction Fator when 2 Pass Shell Side" |
---|
| 1067 | Method.Fc = ((2*Phi *(lambdaN/lambda1))/(ln(abs((1+Phi *(lambdaN/lambda1))/(1-Phi *(lambdaN/lambda1))))))*(1/lambdaN); |
---|
| 1068 | |
---|
| 1069 | end |
---|
| 1070 | |
---|
| 1071 | |
---|
| 1072 | end |
---|
| 1073 | |
---|
| 1074 | case "Eshell": |
---|
| 1075 | |
---|
| 1076 | " Variable not in use when 1 Pass Shell Side" |
---|
| 1077 | lambdaN =1; |
---|
| 1078 | |
---|
| 1079 | " Variable not in use when 1 Pass Shell Side" |
---|
| 1080 | lambda1 =1; |
---|
| 1081 | |
---|
| 1082 | " Variable not in use when 1 Pass Shell Side" |
---|
| 1083 | Pc = P; |
---|
| 1084 | |
---|
| 1085 | switch LMTDcorrection |
---|
| 1086 | |
---|
| 1087 | case "Bowmann": |
---|
| 1088 | |
---|
| 1089 | #" Variable not in use with Bowmann equation" |
---|
| 1090 | # Phi = 1; |
---|
| 1091 | |
---|
| 1092 | " Variable not in use with Bowmann equation" |
---|
| 1093 | Rho = 1; |
---|
| 1094 | |
---|
| 1095 | |
---|
| 1096 | if R equal 1 |
---|
| 1097 | |
---|
| 1098 | then |
---|
| 1099 | |
---|
| 1100 | "LMTD Correction Fator when 1 Pass Shell Side" |
---|
| 1101 | Method.Fc = (sqrt(2)*P)/((1-P)*ln( abs( ( 2-P*0.585786)/( 2-P*3.414214)))); |
---|
| 1102 | |
---|
| 1103 | else |
---|
| 1104 | |
---|
| 1105 | "LMTD Correction Fator when 1 Pass Shell Side" |
---|
| 1106 | Method.Fc = sqrt(R*R+1)*ln(abs((1-P*R)/(1-P)))/((1-R)*ln( abs( ( 2-P*(R+1-sqrt(R*R+1)))/ ( 2-P*(R + 1 + sqrt(R*R+1)))))); |
---|
| 1107 | |
---|
| 1108 | end |
---|
| 1109 | |
---|
| 1110 | case "Fakeri": |
---|
| 1111 | |
---|
| 1112 | #"Non Dimensional Variable for LMTD Correction Fator in Fakeri Equation " |
---|
| 1113 | # Phi = (sqrt(((Inlet.Hot.T- Outlet.Hot.T)*(Inlet.Hot.T- Outlet.Hot.T))+((Outlet.Cold.T - Inlet.Cold.T)*(Outlet.Cold.T - Inlet.Cold.T))))/(2*((Inlet.Hot.T+ Outlet.Hot.T)-(Inlet.Cold.T+ Outlet.Cold.T))); |
---|
| 1114 | |
---|
| 1115 | "Non Dimensional Variable for LMTD Correction Fator in Fakeri Equation" |
---|
| 1116 | Rho*(1-P*R) = (1-P); |
---|
| 1117 | |
---|
| 1118 | if Rho equal 1 |
---|
| 1119 | |
---|
| 1120 | then |
---|
| 1121 | |
---|
| 1122 | "LMTD Correction Fator when 1 Pass Shell Side" |
---|
| 1123 | Method.Fc = (4*Phi)/(ln(abs((1+2*Phi)/(1-2*Phi)))); |
---|
| 1124 | |
---|
| 1125 | else |
---|
| 1126 | |
---|
| 1127 | "LMTD Correction Fator when 1 Pass Shell Side" |
---|
| 1128 | Method.Fc = (2*Phi*(Rho+1)*ln(abs(Rho)))/( ln(abs((1+2*Phi)/(1-2*Phi)))*(Rho-1)); |
---|
| 1129 | |
---|
| 1130 | end |
---|
| 1131 | |
---|
| 1132 | end |
---|
| 1133 | |
---|
| 1134 | |
---|
| 1135 | end |
---|
| 1136 | |
---|
| 1137 | end |
---|
| 1138 | |
---|