Changeset 450 for branches/packed


Ignore:
Timestamp:
Jan 28, 2008, 4:49:44 PM (15 years ago)
Author:
Paula Bettio Staudt
Message:

A new packed-stage model

Location:
branches/packed/eml/stage_separators
Files:
2 edited

Legend:

Unmodified
Added
Removed
  • branches/packed/eml/stage_separators/column.mso

    r448 r450  
    12911291        top as Integer(Brief="Number of top tray");
    12921292        bot as Integer(Brief="Number of bottom tray");
     1293        H as length (Brief="Height of packing");
    12931294
    12941295        SET
     
    12981299        VARIABLES
    12991300        stage(NTrays) as packedStage;
     1301       
     1302        EQUATIONS
     1303        stage.hs = H/NTrays;
    13001304
    13011305        CONNECTIONS
    13021306        stage([top+topdown:topdown:bot]).OutletV to stage([top:topdown:bot-topdown]).InletV;
    13031307        stage([top:topdown:bot-topdown]).OutletL to stage([top+topdown:topdown:bot]).InletL;
    1304 end
    1305 
     1308       
     1309       
     1310end
     1311
  • branches/packed/eml/stage_separators/tray.mso

    r449 r450  
    277277end
    278278
     279Model packedStage as trayBasic
     280        PARAMETERS
     281        a as Real (Brief="surface area per packing volume", Unit='m^2/m^3');
     282        g as acceleration;
     283        e as Real (Brief="Void fraction of packing, m^3/m^3");
     284        V as volume;
     285        Across as area;
     286        ds as length (Brief="Column diameter");
     287        d as length (Brief="size of an element of packing");
     288        h as length (Brief="Height of packing");
     289        C as Real (Brief="Constant for resitance factor equation");
     290        Cp as Real (Brief="Constant for resitance at loading point factor equation");
     291        Mw(NComp)       as molweight    (Brief = "Component Mol Weight");
     292
     293        SET
     294        Mw = PP.MolecularWeight();
     295       
     296        VARIABLES
     297        niL as viscosity (Brief="Liquid dynamic viscosity", DisplayUnit='kg/m/s');
     298        niV as viscosity (Brief="Vapor dynamic viscosity", DisplayUnit='kg/m/s');
     299        rhoL as dens_mass;
     300        rhoV as dens_mass;
     301        hL as Real (Brief="Liquid holdup", Default = 0.424);
     302        VL as volume (Brief="Liquid volume", Default = 0.025);
     303        uL as velocity (Brief="volume flow rate of liquid, m^3/m^2/s", Default = 0.007);
     304        uV as velocity (Brief="volume flow rate of vapor, m^3/m^2/s", Default = 1.14);
     305        ksi as Real (Brief="Coefficient of Resistance", Default = 0.784);
     306        ksil as Real (Brief="Coefficient of Resistance", Default = 0.032);
     307        Rev as Real(Brief="Vapor Reynolds",Default = 0.966);
     308        hLs as Real(Default = 0.037);
     309        hs as length (Brief="Height of the packing stage");
     310       
     311        EQUATIONS
     312        "Liquid Density"
     313        rhoL = PP.LiquidDensity(OutletL.T, OutletL.P, OutletL.z);
     314        "Vapour Density"
     315        rhoV = PP.VapourDensity(InletV.T, InletV.P, InletV.z);
     316        "Liquid viscosity"
     317        niL = PP.LiquidViscosity(OutletL.T, OutletL.P, OutletL.z);
     318        "Vapour viscosity"
     319        niV = PP.VapourViscosity(InletV.T, InletV.P, InletV.z);
     320        "Liquid volume"
     321        VL = vL * ML;
     322        "Liquid holdup"
     323        hL = VL/V;
     324        "Volume flow rate of liquid, m^3/m^2/s"
     325        uL * Across = OutletL.F * vL;
     326        "volume flow rate of vapor, m^3/m^2/s"
     327        uV * Across = OutletV.F * vV;
     328
     329        "Coefficient of Resistance"
     330        ksi * C^2 * (uL/uV * sqrt(rhoV/rhoL) * (niL/niV)^5.8)^3 = g/1*'s^2/m';
     331        ksil = Cp * (exp(uL*rhoL/a/niL/200)*(hL/hLs)^0.3) * (64/Rev+(1.8/Rev)) *
     332                                ((e-hL)/e);#1.5
     333        "Liquid holdup and Liquid flow"
     334        a^2 * niL * uL = hL^1 *(g*rhoL/3 - ksi*a*rhoV*uV^2/(4*hL*(e-hL)^2));
     335        "Pressure drop and Vapor flow"
     336        (InletV.P - OutletV.P)/hs = ksil *(a/2 + 2/ds)*(uV^2*rhoV/(e-hL)^3);
     337       
     338       
     339        Rev = uV * (d-2*hL/a) * rhoV/ niV;
     340       
     341        hLs = (12*a^2*niL*uL/g/rhoL)^0.333;
     342end
     343
     344
    279345#*-------------------------------------------------------------------
    280346* Model of a tray with reaction
Note: See TracChangeset for help on using the changeset viewer.