Changeset 450 for branches/packed

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:

• column.mso (modified) (2 diffs)
• tray.mso (modified) (1 diff)

branches/packed/eml/stage_separators/column.mso

@@ -1291 +1291 @@
         top as Integer(Brief="Number of top tray");
         bot as Integer(Brief="Number of bottom tray");
+        H as length (Brief="Height of packing");
 
         SET
@@ -1298 +1299 @@
         VARIABLES
         stage(NTrays) as packedStage;
+        
+        EQUATIONS
+        stage.hs = H/NTrays;
 
         CONNECTIONS
         stage([top+topdown:topdown:bot]).OutletV to stage([top:topdown:bot-topdown]).InletV;
         stage([top:topdown:bot-topdown]).OutletL to stage([top+topdown:topdown:bot]).InletL;
-end
-
+        
+        
+end
+

branches/packed/eml/stage_separators/tray.mso

@@ -277 +277 @@
 end
 
+Model packedStage as trayBasic
+        PARAMETERS
+        a as Real (Brief="surface area per packing volume", Unit='m^2/m^3');
+        g as acceleration;
+        e as Real (Brief="Void fraction of packing, m^3/m^3");
+        V as volume;
+        Across as area;
+        ds as length (Brief="Column diameter");
+        d as length (Brief="size of an element of packing");
+        h as length (Brief="Height of packing");
+        C as Real (Brief="Constant for resitance factor equation");
+        Cp as Real (Brief="Constant for resitance at loading point factor equation");
+        Mw(NComp)       as molweight    (Brief = "Component Mol Weight");
+
+        SET
+        Mw = PP.MolecularWeight();
+        
+        VARIABLES
+        niL as viscosity (Brief="Liquid dynamic viscosity", DisplayUnit='kg/m/s');
+        niV as viscosity (Brief="Vapor dynamic viscosity", DisplayUnit='kg/m/s');
+        rhoL as dens_mass;
+        rhoV as dens_mass;
+        hL as Real (Brief="Liquid holdup", Default = 0.424);
+        VL as volume (Brief="Liquid volume", Default = 0.025);
+        uL as velocity (Brief="volume flow rate of liquid, m^3/m^2/s", Default = 0.007);
+        uV as velocity (Brief="volume flow rate of vapor, m^3/m^2/s", Default = 1.14);
+        ksi as Real (Brief="Coefficient of Resistance", Default = 0.784);
+        ksil as Real (Brief="Coefficient of Resistance", Default = 0.032);
+        Rev as Real(Brief="Vapor Reynolds",Default = 0.966);
+        hLs as Real(Default = 0.037);
+        hs as length (Brief="Height of the packing stage");
+        
+        EQUATIONS
+        "Liquid Density"
+        rhoL = PP.LiquidDensity(OutletL.T, OutletL.P, OutletL.z);
+        "Vapour Density"
+        rhoV = PP.VapourDensity(InletV.T, InletV.P, InletV.z);
+        "Liquid viscosity"
+        niL = PP.LiquidViscosity(OutletL.T, OutletL.P, OutletL.z);
+        "Vapour viscosity"
+        niV = PP.VapourViscosity(InletV.T, InletV.P, InletV.z);
+        "Liquid volume"
+        VL = vL * ML;
+        "Liquid holdup"
+        hL = VL/V;
+        "Volume flow rate of liquid, m^3/m^2/s"
+        uL * Across = OutletL.F * vL;
+        "volume flow rate of vapor, m^3/m^2/s"
+        uV * Across = OutletV.F * vV;
+
+        "Coefficient of Resistance"
+        ksi * C^2 * (uL/uV * sqrt(rhoV/rhoL) * (niL/niV)^5.8)^3 = g/1*'s^2/m';
+        ksil = Cp * (exp(uL*rhoL/a/niL/200)*(hL/hLs)^0.3) * (64/Rev+(1.8/Rev)) *
+                                ((e-hL)/e);#1.5
+        "Liquid holdup and Liquid flow"
+        a^2 * niL * uL = hL^1 *(g*rhoL/3 - ksi*a*rhoV*uV^2/(4*hL*(e-hL)^2));
+        "Pressure drop and Vapor flow"
+        (InletV.P - OutletV.P)/hs = ksil *(a/2 + 2/ds)*(uV^2*rhoV/(e-hL)^3);
+        
+        
+        Rev = uV * (d-2*hL/a) * rhoV/ niV;
+        
+        hLs = (12*a^2*niL*uL/g/rhoL)^0.333;
+end
+
+
 #*-------------------------------------------------------------------
 * Model of a tray with reaction