Ignore:
Timestamp:
Oct 8, 2009, 4:38:37 PM (13 years ago)
Author:
gerson bicca
Message:

packed column revised

File:
1 edited

Legend:

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Added
Removed
  • branches/gui/eml/stage_separators/tray.mso

    r849 r850  
    298298";     
    299299       
    300        
    301300PARAMETERS
    302301
    303302outer PP as Plugin(Brief = "External Physical Properties", Type="PP");
    304303outer NComp as Integer;
    305 #*     
    306 outer ColumnDiameter            as length               (Brief="Column diameter");
    307 outer AreaPerPackingVol as Real (Brief="Surface area per packing volume", Unit='m^2/m^3');
    308 outer VoidFraction as fraction (Brief="Void fraction of packing, m^3/m^3");
    309 outer hs as length (Brief="Height of the packing stage");
    310 outer ResistanceCoeff as positive (Brief="Resistance coefficient on the liquid load", Default = 0.6);
    311 *#
    312         ColumnDiameter          as length               (Brief="Column diameter");
    313         AreaPerPackingVol as Real (Brief="Surface area per packing volume", Unit='m^2/m^3');
    314         VoidFraction as fraction (Brief="Void fraction of packing, m^3/m^3");
    315         hs as length (Brief="Height of the packing stage");
    316         ResistanceCoeff as positive (Brief="Resistance coefficient on the liquid load", Default = 0.6);
    317 
    318         V as volume (Brief="Total volume of the tray");
    319         HeatSupply      as heat_rate    (Brief="Rate of heat supply");
    320         Gconst          as acceleration (Brief="Gravity Acceleration",Default=9.81,Hidden=true);
     304
    321305        Mw(NComp)       as molweight    (Brief = "Component Mol Weight");
    322         VapourFlow as Switcher (Valid=["on", "off"], Default = "on");
    323        
    324306       
    325307VARIABLES
    326308
    327309        Inlet                   as stream                               (Brief="Feed stream", PosX=0, PosY=0.4932, Symbol="_{in}");
    328 
    329 in      InletLiquid     as stream                               (Brief="Inlet liquid stream", PosX=0.5195, PosY=0, Symbol="_{inL}");
    330 in      InletVapour     as stream                               (Brief="Inlet vapour stream", PosX=0.4994, PosY=1, Symbol="_{inV}");
     310in      InletLiquid                     as stream                               (Brief="Inlet liquid stream", PosX=0.5195, PosY=0, Symbol="_{inL}");
     311in      InletVapour                     as stream                               (Brief="Inlet vapour stream", PosX=0.4994, PosY=1, Symbol="_{inV}");
    331312out     OutletLiquid    as liquid_stream        (Brief="Outlet liquid stream", PosX=0.8277, PosY=1, Symbol="_{outL}");
    332313out     OutletVapour    as vapour_stream        (Brief="Outlet vapour stream", PosX=0.8043, PosY=0, Symbol="_{outV}");
     
    344325        rhoV as dens_mass;
    345326       
    346         deltaP as pressure (Lower = -10);
    347        
    348         uL as velocity (Brief="volume flow rate of liquid, m^3/m^2/s", Lower=0, Upper=100);
    349         uV as velocity (Brief="volume flow rate of vapor, m^3/m^2/s", Lower=-0, Upper=100);
     327        deltaP as pressure;
     328       
     329        uL as velocity (Brief="volume flow rate of liquid, m^3/m^2/s", Lower=-10, Upper=100);
     330        uV as velocity (Brief="volume flow rate of vapor, m^3/m^2/s", Lower=-10, Upper=100);
    350331        #dp as length (Brief="Particle diameter", Default=1e-3, Lower=0, Upper=10);
    351332        #invK as positive (Brief="Wall factor", Default=1, Upper=10);
    352333        #Rev as Real (Brief="Reynolds number of the vapor stream", Default=4000);
    353         Al as area (Brief="Area occupied by the liquid", Default=0.001, Upper=10);
    354         hl as positive (Brief="Column holdup", Unit='m^3/m^3', Default=0.04,Upper=1);
    355 
     334        Al as area (Brief="Area occupied by the liquid", Default=0.001, Upper=1);
     335        hl as positive (Brief="Column holdup", Unit='m^3/m^3', Default=0.01,Upper=10);
    356336
    357337SET
    358338        Mw = PP.MolecularWeight();
    359339
    360 
    361340EQUATIONS
    362341
     
    364343        diff(M)=Inlet.F*Inlet.z + InletLiquid.F*InletLiquid.z + InletVapour.F*InletVapour.z- OutletLiquid.F*OutletLiquid.z - OutletVapour.F*OutletVapour.z;
    365344
    366 "Energy Balance"
    367     diff(E) = ( Inlet.F*Inlet.h + InletLiquid.F*InletLiquid.h + InletVapour.F*InletVapour.h - OutletLiquid.F*OutletLiquid.h - OutletVapour.F*OutletVapour.h + HeatSupply);
    368 
    369345"Molar Holdup"
    370346        M = ML*OutletLiquid.z + MV*OutletVapour.z;
    371347       
    372 "Energy Holdup"
    373     E = ML*OutletLiquid.h + MV*OutletVapour.h - OutletLiquid.P*V;       
    374        
    375348"Mol fraction normalisation"
    376349        sum(OutletLiquid.z)= 1.0;
    377         sum(OutletLiquid.z)=sum(OutletVapour.z);
     350        sum(OutletLiquid.z)= sum(OutletVapour.z);
    378351       
    379352"Liquid Volume"
     
    392365        OutletLiquid.P = OutletVapour.P;
    393366       
    394 "Geometry Constraint"
    395     V*VoidFraction = ML*vL + MV*vV;
    396 
    397367"Liquid Density"
    398368        rhoL = PP.LiquidDensity(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z);
     
    405375
    406376#"Vapour viscosity"
    407 #       miV = PP.VapourViscosity(InletVapour.T, InletVapour.P, InletVapour.z);
    408 
    409 "Area occupied by the liquid"
    410         Al = ML*vL/hs;
     377 #      miV = PP.VapourViscosity(InletVapour.T, InletVapour.P, InletVapour.z);
    411378
    412379"Volume flow rate of liquid, m^3/m^2/s"
    413380        uL * Al = OutletLiquid.F * vL;
    414381       
    415 "Volume flow rate of vapour, m^3/m^2/s"
    416         uV * (V*VoidFraction/hs - Al) = InletVapour.F * vV;
    417        
    418 "Liquid holdup"
    419     hl*V*VoidFraction = ML*vL;
    420 
    421 "Liquid velocity as a function of liquid holdup, Billet (4-27)"
    422         hl^3 = (12/Gconst) * AreaPerPackingVol^2 * (miL/rhoL) * uL;
    423                
    424         switch VapourFlow
    425                 case "on":
    426                         "Pressure drop and Vapor flow, Billet (4-58)"
    427                                 deltaP/hs  = ResistanceCoeff * (AreaPerPackingVol/2 + 2/ColumnDiameter) * 1/((VoidFraction-hl)^3) * (uV^2) * rhoV;
    428    
    429             when InletVapour.F < 1e-6 * 'kmol/h' switchto "off";
    430 
    431 
    432         case "off":
    433                         InletVapour.F = 0 * 'mol/s';
    434                         when deltaP > 1e-4 * 'atm' switchto "on";
    435     end
    436        
    437 "Pressure profile"
    438     deltaP = InletVapour.P - OutletVapour.P;
     382        deltaP = InletVapour.P - OutletVapour.P;
    439383       
    440384end
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