Changeset 503 for branches/rate


Ignore:
Timestamp:
Apr 15, 2008, 5:48:57 PM (14 years ago)
Author:
Gabriela Sporleder Straatmann
Message:

Starting rate model for tray.mso

File:
1 edited

Legend:

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  • branches/rate/eml/stage_separators/tray.mso

    r498 r503  
    472472        hl = (12*miL*a^2*uL/rhoL/g)^1/3;
    473473end
     474
     475Model trayRate
     476        ATTRIBUTES
     477        Pallete         = false;
     478        Icon            = "icon/Tray";
     479        Brief           = "Basic equations of a tray column model.";
     480        Info            =
     481"This model contains only the main equations of a column tray equilibrium model without
     482the hidraulic equations.
     483       
     484== Assumptions ==
     485* both phases (liquid and vapour) exists all the time;
     486* thermodymanic equilibrium with Murphree plate efficiency;
     487* no entrainment of liquid or vapour phase;
     488* no weeping;
     489* the dymanics in the downcomer are neglected.
     490";
     491       
     492        PARAMETERS
     493outer PP as Plugin(Brief = "External Physical Properties", Type="PP");
     494outer NComp as Integer;
     495        V as volume(Brief="Total Volume of the tray");
     496        Q as heat_rate (Brief="Rate of heat supply");
     497        Ap as area (Brief="Plate area = Atray - Adowncomer");
     498       
     499        VARIABLES
     500in      Inlet as stream (Brief="Feed stream", PosX=0, PosY=0.4932, Symbol="_{in}");
     501in      InletL as stream (Brief="Inlet liquid stream", PosX=0.5195, PosY=0, Symbol="_{inL}");
     502in      InletV as stream (Brief="Inlet vapour stream", PosX=0.4994, PosY=1, Symbol="_{inV}");
     503out     OutletL as liquid_stream (Brief="Outlet liquid stream", PosX=0.8277, PosY=1, Symbol="_{outL}");
     504out     OutletV as vapour_stream (Brief="Outlet vapour stream", PosX=0.8043, PosY=0, Symbol="_{outV}");
     505
     506        M(NComp) as mol (Brief="Molar Holdup in the tray");
     507        ML as mol (Brief="Molar liquid holdup");
     508        MV as mol (Brief="Molar vapour holdup");
     509        E as energy (Brief="Total Energy Holdup on tray");
     510        vL as volume_mol (Brief="Liquid Molar Volume");
     511        vV as volume_mol (Brief="Vapour Molar volume");
     512        Level as length (Brief="Height of clear liquid on plate");
     513        yideal(NComp) as fraction;
     514        Emv as Real (Brief = "Murphree efficiency");
     515       
     516        EQUATIONS
     517        "Component Molar Balance"
     518        diff(M)=Inlet.F*Inlet.z + InletL.F*InletL.z + InletV.F*InletV.z
     519                - OutletL.F*OutletL.z - OutletV.F*OutletV.z;
     520       
     521        "Energy Balance"
     522        diff(E) = ( Inlet.F*Inlet.h + InletL.F*InletL.h + InletV.F*InletV.h
     523                - OutletL.F*OutletL.h - OutletV.F*OutletV.h + Q );
     524       
     525        "Molar Holdup"
     526        M = ML*OutletL.z + MV*OutletV.z;
     527       
     528        "Energy Holdup"
     529        E = ML*OutletL.h + MV*OutletV.h - OutletL.P*V;
     530       
     531        "Mol fraction normalisation"
     532        sum(OutletL.z)= 1.0;
     533        sum(OutletL.z)= sum(OutletV.z);
     534       
     535        "Liquid Volume"
     536        vL = PP.LiquidVolume(OutletL.T, OutletL.P, OutletL.z);
     537        "Vapour Volume"
     538        vV = PP.VapourVolume(OutletV.T, OutletV.P, OutletV.z);
     539       
     540        "Chemical Equilibrium"
     541        PP.LiquidFugacityCoefficient(OutletL.T, OutletL.P, OutletL.z)*OutletL.z =
     542                PP.VapourFugacityCoefficient(OutletV.T, OutletV.P, yideal)*yideal;
     543
     544        "Murphree Efficiency"
     545        OutletV.z = Emv * (yideal - InletV.z) + InletV.z;
     546       
     547        "Thermal Equilibrium"
     548        OutletV.T = OutletL.T;
     549       
     550        "Mechanical Equilibrium"
     551        OutletV.P = OutletL.P;
     552       
     553        "Geometry Constraint"
     554        V = ML* vL + MV*vV;
     555       
     556        "Level of clear liquid over the weir"
     557        Level = ML*vL/Ap;
     558end
     559
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