Ignore:
Timestamp:
Jul 18, 2009, 5:08:06 PM (13 years ago)
Author:
gerson bicca
Message:

updated tank model (vertical/horizontal orientation with heads flat,elliptical or hemispherical)

File:
1 edited

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  • branches/gui/eml/stage_separators/tank.mso

    r794 r795  
    1212* EMSO is distributed under the therms of the ALSOC LICENSE as
    1313* available at http://www.enq.ufrgs.br/alsoc.
    14 *
    15 *-------------------------------------------------------------------
    16 * Model of tanks
    17 *--------------------------------------------------------------------
    18 *       Streams:
    19 *               * an inlet stream
    20 *               * an outlet stream
    21 *
    22 *       Specify:
    23 *               * the Inlet stream
    24 *               * the Outlet flow
    25 *               * the tank Q
    26 *
    27 *       Initial:
    28 *               * the tank temperature (OutletL.T)
    29 *               * the tank level (h)
    30 *               * (NoComps - 1) Outlet compositions
    3114*----------------------------------------------------------------------
    3215* Author: Paula B. Staudt
     
    124107end
    125108
    126 Model RefluxDrum
     109Model TankVL
    127110
    128111ATTRIBUTES
    129112        Pallete         = true;
    130         Icon            = "icon/RefluxDrum";
    131         Brief           = "Model of a Reflux Drum with a lain cylinder geometry.";
     113        Icon            = "icon/TankVL";
     114        Brief           = "Model of a Tank With Thermodynamic Equilibrium.";
     115        Info            =
     116"== ASSUMPTIONS ==
     117* perfect mixing of both phases;
     118* thermodynamics equilibrium.
     119
     120== SET ==
     121*Orientation: vessel position - vertical or horizontal;
     122*Heads (bottom and top heads are identical)
     123**elliptical: 2:1 elliptical heads (25% of vessel diameter);
     124**hemispherical: hemispherical heads (50% of vessel diameter);
     125**flat: flat heads (0% of vessel diameter);
     126*Diameter: Vessel diameter;
     127*Lenght: Side length of the cylinder shell;
     128       
     129== SPECIFY ==
     130* the Inlet stream;
     131* the outlet flows: OutletVapour.F and OutletLiquid.F;
     132* the InletQ (the model requires an energy stream, also you can use a controller for setting the heat duty using the heat_flow model).
     133
     134== OPTIONAL ==
     135* the TankVL model has three control ports
     136** TI OutletLiquid Temperature Indicator;
     137** PI OutletLiquid Pressure Indicator;
     138** LI Level Indicator;
     139
     140== INITIAL CONDITIONS ==
     141* Initial_Temperature :  the Tank temperature (OutletLiquid.T);
     142* Initial_Level : the Tank liquid level (Level);
     143* Initial_Composition : (NoComps) OutletLiquid compositions.
     144";
     145       
     146PARAMETERS
     147outer PP                as Plugin       (Brief = "External Physical Properties", Type="PP");
     148outer NComp     as Integer      (Brief = "Number of components", Lower = 1);
     149
     150        Mw(NComp)               as molweight    (Brief="Mol Weight", Hidden=true);
     151        pi                      as positive             (Brief="Pi value", Default=3.141593,Hidden=true, Symbol="\pi");
     152       
     153        Orientation     as Switcher     (Valid=["vertical","horizontal"],Default="vertical");
     154        Heads                   as Switcher     (Valid=["elliptical","hemispherical","flat"],Default="flat");
     155        Diameter                as length               (Brief="Vessel diameter", Symbol="D_{i}");
     156        Lenght                  as length               (Brief="Side length of the cylinder shell", Symbol="L_{vessel}");
     157       
     158        Vhead_elliptical                as volume               (Brief="Elliptical Head Total Volume",Hidden=true, Symbol="V_{head}^{elliptical}");
     159        Vhead_hemispherical     as volume               (Brief="Hemispherical Head Total Volume",Hidden=true, Symbol="V_{head}^{hemispherical}");
     160        Vcylinder                               as volume               (Brief="Cylinder Total Volume",Hidden=true, Symbol="V_{cylinder}");
     161        radius                                  as length               (Brief="Vessel radius",Hidden=true, Symbol="R_{cylinder}");
     162       
     163        Levelpercent_Initial                    as positive     (Brief="Initial liquid height in Percent", Default = 0.70);
     164        Temperature_Initial                             as temperature  (Brief="Initial Liquid Temperature", Default = 330);
     165        Composition_Initial(NComp)              as fraction             (Brief="Initial Composition", Default = 0.10);
     166
     167SET
     168
     169        Mw=PP.MolecularWeight();
     170
     171        Vhead_elliptical        = (pi*Diameter^3)/12;
     172        Vhead_hemispherical = (pi*Diameter^3)/6;
     173        Vcylinder = 0.25*(pi*Diameter^2)*Lenght;
     174        radius = 0.5*Diameter;
     175
     176VARIABLES
     177
     178in      Inlet                   as stream                       (Brief="Feed Stream", PosX=0.22, PosY=0, Symbol="_{in}");
     179out     OutletLiquid    as liquid_stream        (Brief="Liquid outlet stream", PosX=0.43, PosY=1, Symbol="_{out}^{Liquid}");
     180out     OutletVapour    as vapour_stream        (Brief="Vapour outlet stream", PosX=0.68, PosY=0, Symbol="_{out}^{Vapour}");
     181in      InletQ                  as power                        (Brief="Heat Duty", PosX=0.735, PosY=1, Protected =true,Symbol="Q_{in}");
     182
     183        Vtotal                  as volume                       (Brief="Vessel total volume",Protected=true, Symbol="V_{total}");
     184        Vfilled                 as volume                       (Brief="Vessel volume content",Protected=true, Symbol="V_{filled}");
     185
     186        TotalHoldup(NComp)              as mol  (Brief="Molar Holdup in the Vessel", Protected=true);
     187        LiquidHoldup                    as mol  (Brief="Molar liquid holdup", Protected=true);
     188        VapourHoldup                    as mol  (Brief="Molar vapour holdup", Protected=true);
     189       
     190        E                       as energy               (Brief="Total Energy Holdup in the Vessel", Protected=true);
     191        vL                      as volume_mol   (Brief="Liquid Molar Volume", Protected=true);
     192        vV                      as volume_mol   (Brief="Vapour Molar volume", Protected=true);
     193        Level           as length               (Brief="liquid height", Protected=true);
     194        Across          as area                 (Brief="Vessel cylinder shell Cross section area", Hidden=true, Symbol="A_{cross}");
     195        vfrac           as positive     (Brief="Vapourization fraction", Symbol="\phi", Protected=true);
     196        Pratio          as positive             (Brief = "Pressure Ratio", Symbol ="P_{ratio}", Protected=true);       
     197        Pdrop           as press_delta  (Brief = "Pressure Drop", DisplayUnit = 'kPa', Symbol ="\Delta P", Protected=true);
     198
     199out     TI as control_signal    (Brief="Temperature Indicator", PosX=0.525, PosY=0, Protected=true);
     200out     PI as control_signal    (Brief="Pressure Indicator", PosX=0.368, PosY=0, Protected=true);
     201out     LI as control_signal    (Brief="Level Indicator", PosX=1, PosY=0.6, Protected=true);
     202
     203INITIAL
     204
     205"Initial level Percent"
     206        LI = Levelpercent_Initial;
     207       
     208"Initial Outlet Liquid Temperature"
     209        OutletLiquid.T = Temperature_Initial;
     210       
     211"Initial Outlet Liquid Composition Normalized"
     212        OutletLiquid.z(1:NComp - 1) = Composition_Initial(1:NComp - 1)/sum(Composition_Initial);
     213
     214EQUATIONS
     215
     216switch Orientation
     217
     218case "vertical":
     219
     220"Vessel Cross Section Area"
     221        Across = 0.25*(pi*Diameter^2);
     222
     223switch Heads
     224
     225case "elliptical":
     226
     227"Vessel Total Volume"
     228        Vtotal = Vhead_elliptical +     Vcylinder;
     229
     230if Level < 0.25*Diameter then
     231
     232"Vessel Filled Volume"
     233        Vfilled = 0.25*pi*(((Diameter*Level)/(0.25*Diameter))^2)*(0.25*Diameter-Level/3);
     234
     235else
     236
     237"Vessel Filled Volume"
     238        Vfilled = 0.25*pi*(Diameter^2)*(Level - 0.25*Diameter/3);
     239
     240end
     241
     242case "hemispherical":
     243
     244"Vessel Total Volume"
     245        Vtotal = Vhead_hemispherical + Vcylinder;
     246
     247if Level < 0.5*Diameter then
     248
     249"Vessel Filled Volume"
     250        Vfilled = 0.25*pi*(Level^2)*(2*Diameter-4*Level/3);
     251
     252else
     253
     254"Vessel Filled Volume"
     255        Vfilled = 0.25*pi*((2/3)*((0.5*Diameter)^3) - (0.25*(Diameter)^3) + Level*Diameter^2);
     256
     257end
     258
     259case "flat":
     260
     261"Vessel Total Volume"
     262        Vtotal = Vcylinder;
     263
     264"Vessel Filled Volume"
     265        Vfilled = Across*Level;
     266
     267end
     268
     269case "horizontal":
     270
     271"Vessel Cross Section Area"
     272        Across = (radius^2)*acos((radius-Level)/radius)-(radius-Level)*sqrt((2*radius*Level-Level^2));
     273
     274switch Heads
     275
     276case "elliptical":
     277
     278"Vessel Total Volume"
     279        Vtotal = Vhead_elliptical +     Vcylinder;
     280
     281"Vessel Filled Volume"
     282        Vfilled = 0.5236*Level^2*(1.5*Diameter-Level) + Across*Lenght;
     283
     284case "hemispherical":
     285
     286"Vessel Total Volume"
     287        Vtotal = Vhead_hemispherical + Vcylinder;
     288
     289"Vessel Filled Volume"
     290        Vfilled = 1.0472*Level^2*(1.5*Diameter-Level) + Across*Lenght;
     291
     292case "flat":
     293
     294"Vessel Total Volume"
     295        Vtotal = Vcylinder;
     296
     297"Vessel Filled Volume"
     298        Vfilled = Across*Lenght;
     299
     300end
     301
     302end
     303
     304"Component Molar Balance"
     305        diff(TotalHoldup)=Inlet.F*Inlet.z - OutletLiquid.F*OutletLiquid.z - OutletVapour.F*OutletVapour.z;
     306       
     307"Energy Balance"
     308        diff(E) = Inlet.F*Inlet.h - OutletLiquid.F*OutletLiquid.h - OutletVapour.F*OutletVapour.h + InletQ;
     309       
     310"Molar Holdup"
     311        TotalHoldup = LiquidHoldup*OutletLiquid.z + VapourHoldup*OutletVapour.z;
     312       
     313"Energy Holdup"
     314        E = LiquidHoldup*OutletLiquid.h + VapourHoldup*OutletVapour.h - OutletLiquid.P*Vtotal;
     315       
     316"Mol fraction normalisation"
     317        sum(OutletLiquid.z)=1.0;
     318
     319"Mol fraction normalisation"
     320        sum(OutletLiquid.z)=sum(OutletVapour.z);
     321
     322"Vaporization Fraction"
     323        OutletVapour.F = Inlet.F * vfrac;
     324
     325"Liquid Volume"
     326        vL = PP.LiquidVolume(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z);
     327
     328"Vapour Volume"
     329        vV = PP.VapourVolume(OutletVapour.T, OutletVapour.P, OutletVapour.z);
     330       
     331"Chemical Equilibrium"
     332        PP.LiquidFugacityCoefficient(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z)*OutletLiquid.z =
     333                PP.VapourFugacityCoefficient(OutletVapour.T, OutletVapour.P, OutletVapour.z)*OutletVapour.z;
     334       
     335"Thermal Equilibrium"
     336        OutletVapour.T = OutletLiquid.T;
     337       
     338"Mechanical Equilibrium"
     339        OutletVapour.P = OutletLiquid.P;
     340
     341"Pressure Drop"
     342        OutletLiquid.P  = Inlet.P - Pdrop;
     343
     344"Pressure Ratio"
     345        OutletLiquid.P = Inlet.P * Pratio;
     346
     347"Geometry Constraint"
     348        Vtotal = LiquidHoldup * vL + VapourHoldup * vV;
     349
     350"Temperature indicator"
     351        TI * 'K' = OutletLiquid.T;
     352
     353"Pressure indicator"
     354        PI * 'atm' = OutletLiquid.P;
     355
     356"Level indicator"
     357        LI*Vtotal= Vfilled;
     358
     359"Liquid Level"
     360        LiquidHoldup * vL = Vfilled;
     361
     362end
     363
     364Model tank_cylindrical
     365        ATTRIBUTES
     366        Pallete         = true;
     367        Icon            = "icon/TankHorizontal";
     368        Brief           = "Model of a tank with a lain cylinder geometry.";
    132369        Info            =
    133370"== Specify ==
     
    157394
    158395SET
    159         radius = 0.5*Diameter;
     396        radius = Diameter/2;
    160397
    161398VARIABLES
     
    216453end
    217454
    218 Model tank_cylindrical
    219         ATTRIBUTES
    220         Pallete         = true;
    221         Icon            = "icon/TankHorizontal";
    222         Brief           = "Model of a tank with a lain cylinder geometry.";
    223         Info            =
    224 "== Specify ==
    225 * the Inlet stream;
    226 * the outlet flow;
    227 * the InletQ (requires an energy source).
    228 
    229 == Initial Conditions ==
    230 * the tank initial temperature;
    231 * the tank initial level;
    232 * the tank initial composition.
    233 ";
    234        
    235 PARAMETERS
    236         outer PP                as Plugin               (Brief = "External Physical Properties", Type="PP");
    237         outer NComp     as Integer              (Brief = "Number of Components");
    238        
    239         pi                      as positive     (Brief="Pi value", Default=3.141593,Hidden=true);
    240         eps                     as positive     (Brief="small number",Default=1E-8,Hidden=true);
    241         Diameter                as length       (Brief="Tank internal Diameter",Default=1.5);
    242         radius                  as length       (Brief="Tank radius",Hidden=true);
    243         L                               as length       (Brief="Tank length",Default=5);
    244        
    245         Initial_Level                           as length               (Brief="Initial Level of the Tank",Default=1);
    246         Initial_Temperature                     as temperature  (Brief="Initial Temperature of Liquid",Default=300);
    247         Initial_Composition(NComp)      as positive     (Brief="Initial Liquid Composition",Lower=1E-8,Default=0.1);
    248 
    249 SET
    250         radius = Diameter/2;
    251 
    252 VARIABLES
    253 in      Inlet           as stream                       (Brief="Inlet stream", PosX=0.1825, PosY=0, Symbol="_{in}");
    254 out     Outlet          as liquid_stream        (Brief="Outlet liquid stream", PosX=1, PosY=1, Symbol="_{out}");
    255 in      InletQ          as power                        (Brief="Rate of heat supply", PosX=1, PosY=0.6160, Symbol="_{in}",Protected=true);
    256         Level           as length                       (Brief="Tank level",Protected=true);
    257         Vtotal          as volume                       (Brief="Tank total volume",Protected=true);
    258         Vfilled         as volume                       (Brief="Tank volume content",Protected=true);
    259         Across          as area                         (Brief="Tank cross section area", Default=2,Protected=true);
    260         E                       as energy                       (Brief="Total Energy Holdup on tank",Protected=true);
    261         vL                      as volume_mol           (Brief="Liquid Molar Volume",Protected=true);
    262         M(NComp)        as mol                          (Brief="Molar Holdup in the tank",Protected=true);
    263 
    264 INITIAL
    265 
    266 "Initial Level"
    267         Level = Initial_Level;
    268 
    269 "Initial Liquid Temperature"   
    270         Outlet.T = Initial_Temperature;
    271 
    272 "Initial Liquid Composition"   
    273         Outlet.z(1:NComp-1) = Initial_Composition(1:NComp-1)/sum(Initial_Composition);
    274 
    275 EQUATIONS
    276 
    277 "Tank total volume"
    278         Vtotal = (0.25*pi*(Diameter)^2)*L;
    279        
    280 "Mass balance"
    281         diff(M) = Inlet.F*Inlet.z - Outlet.F*Outlet.z;
    282        
    283 "Energy balance"
    284         diff(E) = Inlet.F*Inlet.h - Outlet.F*Outlet.h + InletQ;
    285 
    286 "Energy Holdup"
    287         E = sum(M)*Outlet.h;
    288        
    289 "Mechanical Equilibrium"
    290         Inlet.P = Outlet.P;
    291        
    292 "Liquid Volume"
    293         vL = PP.LiquidVolume(Outlet.T, Outlet.P, Outlet.z);
    294        
    295 "Composition"
    296         M = Outlet.z*sum(M);
    297        
    298 "Cylindrical Area"
    299         Across = radius^2 * (asin(1) - asin((radius-Level)/radius) ) + (Level-radius)*sqrt(Level*(2*radius - Level)+eps*'m^2');
    300 
    301 "Level of liquid phase"
    302         L*Across = sum(M)*vL;
    303 
    304 "Volume Filled of liquid phase"
    305         Vfilled = L*Across;
    306 
    307 end
    308 
    309455Model tank_feed
    310456        ATTRIBUTES
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