Changeset 517

Timestamp:

May 19, 2008, 11:29:24 AM (15 years ago)

Author:

Argimiro Resende Secchi

Message:

Updating tray rate model.

Location:

branches/rate

Files:

• eml/stage_separators/tray.mso (modified) (6 diffs)
• sample/stage_separators/sample_tray.mso (modified) (1 diff)

branches/rate/eml/stage_separators/tray.mso

@@ -119 +119 @@
 == Initial ==
 * the plate temperature (OutletL.T)
-* the liquid height (Level) OR the liquid flow OutletL.F
+* the liquid height (Level) OR the liquid holdup (ML)
 * (NoComps - 1) OutletL compositions
 ";      
@@ -494 +494 @@
         
         VARIABLES
-        NL(NComp) as flow_mol   (Brief = "Stream Molar Rate on Liquid Phase");
-        NV(NComp) as flow_mol   (Brief = "Stream Molar Rate on Vapour Phase");
+        NL(NComp) as flow_mol_delta     (Brief = "Stream Molar Rate on Liquid Phase");
+        NV(NComp) as flow_mol_delta     (Brief = "Stream Molar Rate on Vapour Phase");
         T as temperature                (Brief = "Stream Temperature");
         P as pressure                   (Brief = "Stream Pressure");
@@ -519 +519 @@
 end
 
-Model trayRate 
+Model trayRateBasic
         ATTRIBUTES
         Pallete         = false;
         Icon            = "icon/Tray"; 
-        Brief           = "Basic equations of a tray column model.";
+        Brief           = "Basic equations of a tray rate column model.";
         Info            =
 "This model contains only the main equations of a column tray nonequilibrium model without
@@ -561 +561 @@
         Level as length (Brief="Height of clear liquid on plate");
         interf as interface;    
-        
+
+        SET   
+        NC1=NComp-1;
+
         EQUATIONS
         "Component Molar Balance"
@@ -622 +625 @@
         interf.NL(1:NC1)=interf.a*sumt(interf.kL*(interf.x(1:NC1)-OutletL.z(1:NC1)))/vL+
                 OutletL.z(1:NC1)*sum(interf.NL);
+
+#       interf.NL(1:NC1)=0.01*'kmol/s';
         
         interf.NV(1:NC1)=interf.a*sumt(interf.kV*(OutletV.z(1:NC1)-interf.y(1:NC1)))/vV+
@@ -629 +634 @@
         OutletV.P = OutletL.P;
         interf.P=OutletL.P;
-        
-        SET   
-        NC1=NComp-1;
 end
 
+Model trayRate as trayRateBasic
+        ATTRIBUTES
+        Pallete         = false;
+        Icon            = "icon/Tray"; 
+        Brief           = "Complete rate model of a column tray.";
+        Info            =
+"== Specify ==
+* the Feed stream
+* the Liquid inlet stream
+* the Vapour inlet stream
+* the Vapour outlet flow (OutletV.F)
+        
+== Initial ==
+* the plate temperature of both phases (OutletL.T and OutletV.T)
+* the liquid height (Level) OR the liquid flow holdup (ML)
+* the vapor holdup (MV)
+* (NoComps - 1) OutletL compositions
+";
+
+        PARAMETERS
+        Ah as area (Brief="Total holes area");
+        lw as length (Brief="Weir length");
+        g as acceleration (Default=9.81);
+        hw as length (Brief="Weir height");
+        beta as fraction (Brief="Aeration fraction");
+        alfa as fraction (Brief="Dry pressure drop coefficient");
+        
+        VapourFlow as Switcher(Valid = ["on", "off"], Default = "on");
+        LiquidFlow as Switcher(Valid = ["on", "off"], Default = "on");
+        
+        VARIABLES
+        rhoL as dens_mass;
+        rhoV as dens_mass;
+
+        EQUATIONS
+        "Liquid Density"
+        rhoL = PP.LiquidDensity(OutletL.T, OutletL.P, OutletL.z);
+        "Vapour Density"
+        rhoV = PP.VapourDensity(InletV.T, InletV.P, InletV.z);
+
+        switch LiquidFlow
+                case "on":
+                "Francis Equation"
+#               OutletL.F*vL = 1.84*'m^0.5/s'*lw*((Level-(beta*hw))/(beta))^1.5;
+                OutletL.F*vL = 1.84*'1/s'*lw*((Level-(beta*hw))/(beta))^2;
+                when Level < (beta * hw) switchto "off";
+                
+                case "off":
+                "Low level"
+                OutletL.F = 0 * 'mol/h';
+                when Level > (beta * hw) + 1e-6*'m' switchto "on";
+        end
+
+        switch VapourFlow
+                case "on":
+                InletV.F*vV = sqrt((InletV.P - OutletV.P)/(rhoV*alfa))*Ah;
+                when InletV.F < 1e-6 * 'kmol/h' switchto "off";
+                
+                case "off":
+                InletV.F = 0 * 'mol/s';
+                when InletV.P > OutletV.P + Level*g*rhoL + 1e-1 * 'atm' switchto "on";
+        end     
+end

branches/rate/sample/stage_separators/sample_tray.mso

@@ -243 +243 @@
         
         SPECIFY
-        feed.Outlet.F = 113.4 * 'kmol/h';
-        feed.Outlet.T = 291 * 'K';
-        feed.Outlet.P = 1.66 * 'atm';
+        feed.Outlet.F = 116 * 'kmol/h';
+        feed.Outlet.T = 280 * 'K';
+        feed.Outlet.P = 150 * 'kPa';
         feed.Outlet.z = [0.5, 0.5];
-        
+
         feedV.Outlet.F = 0 * 'kmol/h';
-        feedV.Outlet.T = 291 * 'K';
-        feedV.Outlet.P = 1.66 * 'atm';
+        feedV.Outlet.T = 280 * 'K';
+        feedV.Outlet.P = 150 * 'atm';
         feedV.Outlet.z = [0.5, 0.5];
-        
-        inL.P = 165 * 'kPa';
-        inL.T = 310 * 'K';
-        inL.F = 61.99 * 'kmol/h';
+
+        inL.P = 150 * 'kPa';
+        inL.T = 290 * 'K';
+        inL.F = 62 * 'kmol/h';
         inL.z = [0.1641, 0.8359];
 
         inV.P = 150 * 'kPa';
-        inV.T = 321 * 'K';
+        inV.T = 340 * 'K';
         inV.z = [0.0584, 0.9416];
-        inV.F = 61.99 * 'kmol/h';
-        
-        #t1.Emv = 1;
-        t1.OutletV.F = 147.1 * 'kmol/h';
-        t1.OutletL.F = 147.1 * 'kmol/h';
-        t1.interf.a=0.01*'m^2';
-        t1.interf.htL=0.4*'kW/m^2/K';
-        t1.interf.htV=0.4*'kW/m^2/K';
-        t1.interf.kL=0.001*'m/s';
-        t1.interf.kV=0.001*'m/s';
+#       inV.F = 62 * 'kmol/h';
+
+        t1.OutletV.F = 120 * 'kmol/h';
+#       t1.OutletL.F = 120 * 'kmol/h';
+        t1.interf.a = 140 * 'm^2';
+        t1.interf.htL = 10.01 * 'kW/m^2/K';
+        t1.interf.htV = 0.025 * 'kW/m^2/K';
+        t1.interf.kL = 0.00933 * 'm/s';
+        t1.interf.kV = 0.000236 * 'm/s';
 
         SET
         t1.V = 4 * 'ft^3';
-        #*t1.Ah = 0.394 * 'ft^2';
+        t1.Ah = 0.394 * 'ft^2';
         t1.lw = 20.94 * 'in';
         t1.hw = 0.125 * 'ft';
         t1.beta = 0.6;
-        t1.alfa = 4;*#
-        
+        t1.alfa = 4;
         t1.Ap = 3.94 * 'ft^2';
         t1.Q = 0 * 'kW';
-        
-        INITIAL
-        t1.OutletL.T = 290 *'K';
+
+        INITIAL
+        t1.OutletL.T = 295 *'K';
         t1.OutletV.T = 290 *'K';
-        t1.Level = 0.9*'m' ;
+        t1.Level = 0.9 * t1.hw;
         t1.OutletL.z(1) = 0.5;
-        t1.OutletV.z(1) = 0.5;
-        t1.MV = 0.01*'mol' ;
-        
+        t1.OutletV.z(1) = 0.6;
+        t1.MV = 1.0*'mol' ;
+
         OPTIONS
         TimeStep = 0.1;
-        TimeEnd = 100;
+        TimeEnd = 10;
         TimeUnit = 's';
-#       GuessFile = "tray_Test.rlt";
-end
+        GuessFile = "trayRate_Test.rlt";
+end