source: branches/gui/eml/stage_separators/tank.mso @ 879

Last change on this file since 879 was 879, checked in by gerson bicca, 13 years ago

updated dynamic models

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[1]1#*-------------------------------------------------------------------
[72]2* EMSO Model Library (EML) Copyright (C) 2004 - 2007 ALSOC.
3*
4* This LIBRARY is free software; you can distribute it and/or modify
5* it under the therms of the ALSOC FREE LICENSE as available at
6* http://www.enq.ufrgs.br/alsoc.
7*
8* EMSO Copyright (C) 2004 - 2007 ALSOC, original code
9* from http://www.rps.eng.br Copyright (C) 2002-2004.
10* All rights reserved.
11*
12* EMSO is distributed under the therms of the ALSOC LICENSE as
13* available at http://www.enq.ufrgs.br/alsoc.
[1]14*----------------------------------------------------------------------
15* Author: Paula B. Staudt
16* $Id: tank.mso 879 2009-11-09 16:11:31Z bicca $
17*--------------------------------------------------------------------*#
18
19using "streams";
20
[879]21Model VesselVolume
[794]22
23ATTRIBUTES
[879]24        Pallete         = false;
25        Brief           = "Model to calculate vessel total volume and vessel filled volume from
26different geometries and orientations.";
[794]27        Info            =
[879]28"== SET ==
[795]29*Orientation: vessel position - vertical or horizontal;
30*Heads (bottom and top heads are identical)
31**elliptical: 2:1 elliptical heads (25% of vessel diameter);
32**hemispherical: hemispherical heads (50% of vessel diameter);
33**flat: flat heads (0% of vessel diameter);
34*Diameter: Vessel diameter;
35*Lenght: Side length of the cylinder shell;
[794]36";
37       
38PARAMETERS
[879]39        PI                      as positive             (Brief="Pi value", Default=3.141593,Hidden=true, Symbol="\pi");
40        Gconst                  as acceleration (Brief="Gravity Acceleration",Default=9.81,Hidden=true);
[795]41
42        Orientation     as Switcher     (Valid=["vertical","horizontal"],Default="vertical");
43        Heads                   as Switcher     (Valid=["elliptical","hemispherical","flat"],Default="flat");
[879]44        Diameter                as length               (Brief="Vessel diameter", Default= 2, Symbol="D_{i}");
45        Lenght                  as length               (Brief="Side length of the cylinder shell", Default= 6,  Symbol="L_{vessel}");
[794]46       
[795]47        Vhead_elliptical                as volume               (Brief="Elliptical Head Total Volume",Hidden=true, Symbol="V_{head}^{elliptical}");
48        Vhead_hemispherical     as volume               (Brief="Hemispherical Head Total Volume",Hidden=true, Symbol="V_{head}^{hemispherical}");
49        Vcylinder                               as volume               (Brief="Cylinder Total Volume",Hidden=true, Symbol="V_{cylinder}");
50        radius                                  as length               (Brief="Vessel radius",Hidden=true, Symbol="R_{cylinder}");
[831]51
[794]52SET
[795]53
[879]54        Gconst = 9.81 * 'm/(s^2)';
55        Vhead_elliptical        = (PI*Diameter^3)/12;
56        Vhead_hemispherical = (PI*Diameter^3)/6;
57        Vcylinder = 0.25*(PI*Diameter^2)*Lenght;
[794]58        radius = 0.5*Diameter;
[831]59       
[794]60VARIABLES
61
[879]62        Vtotal          as volume               (Brief="Vessel total volume",Protected=true, Symbol="V_{total}");
63        Vfilled         as volume               (Brief="Vessel volume content",Protected=true, Symbol="V_{filled}");
[795]64        Level           as length               (Brief="liquid height", Protected=true);
65        Across          as area                 (Brief="Vessel cylinder shell Cross section area", Hidden=true, Symbol="A_{cross}");
66       
[794]67EQUATIONS
68
[795]69switch Orientation
70
71case "vertical":
72
73"Vessel Cross Section Area"
[879]74        Across = 0.25*(PI*Diameter^2);
[795]75
76switch Heads
77
78case "elliptical":
79
80"Vessel Total Volume"
81        Vtotal = Vhead_elliptical +     Vcylinder;
82
83if Level < 0.25*Diameter then
84
85"Vessel Filled Volume"
[879]86        Vfilled = 0.25*PI*(((Diameter*Level)/(0.25*Diameter))^2)*(0.25*Diameter-Level/3);
[795]87
88else
89
90"Vessel Filled Volume"
[879]91        Vfilled = 0.25*PI*(Diameter^2)*(Level - 0.25*Diameter/3);
[795]92
93end
94
95case "hemispherical":
96
97"Vessel Total Volume"
98        Vtotal = Vhead_hemispherical + Vcylinder;
99
100if Level < 0.5*Diameter then
101
102"Vessel Filled Volume"
[879]103        Vfilled = 0.25*PI*(Level^2)*(2*Diameter-4*Level/3);
[795]104
105else
106
107"Vessel Filled Volume"
[879]108        Vfilled = 0.25*PI*((2/3)*((0.5*Diameter)^3) - (0.25*(Diameter)^3) + Level*Diameter^2);
[795]109
110end
111
112case "flat":
113
114"Vessel Total Volume"
115        Vtotal = Vcylinder;
116
117"Vessel Filled Volume"
118        Vfilled = Across*Level;
119
120end
121
122case "horizontal":
123
124"Vessel Cross Section Area"
125        Across = (radius^2)*acos((radius-Level)/radius)-(radius-Level)*sqrt((2*radius*Level-Level^2));
126
127switch Heads
128
129case "elliptical":
130
131"Vessel Total Volume"
132        Vtotal = Vhead_elliptical +     Vcylinder;
133
134"Vessel Filled Volume"
135        Vfilled = 0.5236*Level^2*(1.5*Diameter-Level) + Across*Lenght;
136
137case "hemispherical":
138
139"Vessel Total Volume"
140        Vtotal = Vhead_hemispherical + Vcylinder;
141
142"Vessel Filled Volume"
143        Vfilled = 1.0472*Level^2*(1.5*Diameter-Level) + Across*Lenght;
144
145case "flat":
146
147"Vessel Total Volume"
148        Vtotal = Vcylinder;
149
150"Vessel Filled Volume"
151        Vfilled = Across*Lenght;
152
153end
154
155end
156
[879]157end
158
159Model TankVL
160
161ATTRIBUTES
162        Pallete         = true;
163        Icon            = "icon/TankVL";
164        Brief           = "Model of a Tank With Thermodynamic Equilibrium.";
165        Info            =
166"== ASSUMPTIONS ==
167* perfect mixing of both phases;
168* thermodynamics equilibrium.
169
170== SET ==
171*Orientation: vessel position - vertical or horizontal;
172*Heads (bottom and top heads are identical)
173**elliptical: 2:1 elliptical heads (25% of vessel diameter);
174**hemispherical: hemispherical heads (50% of vessel diameter);
175**flat: flat heads (0% of vessel diameter);
176*Diameter: Vessel diameter;
177*Lenght: Side length of the cylinder shell;
178       
179== SPECIFY ==
180* the Inlet stream;
181* the outlet flows: OutletVapour.F and OutletLiquid.F;
182* the InletQ (the model requires an energy stream, also you can use a controller for setting the heat duty using the heat_flow model).
183
184== OPTIONAL ==
185* the TankVL model has three control ports
186** TI OutletLiquid Temperature Indicator;
187** PI OutletLiquid Pressure Indicator;
188** LI Level Indicator;
189
190== INITIAL CONDITIONS ==
191* Initial_Temperature :  the Tank temperature (OutletLiquid.T);
192* Levelpercent_Initial : the Tank liquid level in percent (LI);
193* Initial_Composition : (NoComps) OutletLiquid compositions.
194";
195       
196PARAMETERS
197outer PP                as Plugin       (Brief = "External Physical Properties", Type="PP");
198outer NComp     as Integer      (Brief = "Number of components", Lower = 1);
199
200        Mw(NComp)               as molweight    (Brief="Mol Weight", Hidden=true);
201
202        Gconst          as acceleration (Brief="Gravity Acceleration",Default=9.81,Hidden=true);
203        low_flow        as flow_mol     (Brief = "Low Flow",Default = 1E-6, Hidden=true);
204        zero_flow       as flow_mol     (Brief = "No Flow",Default = 0, Hidden=true);
205        KfConst         as Real                 (Brief="Constant for K factor pressure drop", Unit= 'mol/(s*(Pa^0.5))',Default = 1, Hidden=true);
206        Kfactor as positive (Brief="K factor for pressure drop", Lower = 1E-8, Default = 2);
207       
208        NormalFlow      as Switcher     (Brief="Normal Flow", Valid = ["on", "off"], Default = "on",Hidden=true);
209
210        Levelpercent_Initial                    as positive     (Brief="Initial liquid height in Percent", Default = 0.70);
211        Temperature_Initial                             as temperature  (Brief="Initial Liquid Temperature", Default = 330);
212        Composition_Initial(NComp)              as fraction             (Brief="Initial Composition", Default = 0.10);
213
214SET
215
216        Mw=PP.MolecularWeight();
217        Gconst = 9.81 * 'm/(s^2)';
218        low_flow = 1E-6 * 'kmol/h';
219        zero_flow = 0 * 'kmol/h';
220        KfConst = 1*'mol/(s*(Pa^0.5))';
221
222VARIABLES
223
224        Geometry                as VesselVolume (Brief="Vessel Geometry", Symbol=" ");
225
226in      Inlet                   as stream                       (Brief="Feed Stream", PosX=0.22, PosY=0, Symbol="_{in}");
227out     OutletLiquid    as liquid_stream        (Brief="Liquid outlet stream", PosX=0.43, PosY=1, Symbol="_{out}^{Liquid}");
228out     OutletVapour    as vapour_stream        (Brief="Vapour outlet stream", PosX=0.68, PosY=0, Symbol="_{out}^{Vapour}");
229in      InletQ                  as power                        (Brief="Heat Duty", PosX=0.735, PosY=1, Protected =true,Symbol="Q_{in}");
230
231        TotalHoldup(NComp)              as mol  (Brief="Molar Holdup in the Vessel", Protected=true);
232        LiquidHoldup                    as mol  (Brief="Molar liquid holdup", Protected=true);
233        VapourHoldup                    as mol  (Brief="Molar vapour holdup", Protected=true);
234       
235        E                       as energy               (Brief="Total Energy Holdup in the Vessel", Protected=true);
236        vL                      as volume_mol   (Brief="Liquid Molar Volume", Protected=true);
237        vV                      as volume_mol   (Brief="Vapour Molar volume", Protected=true);
238        Pdrop           as press_delta  (Brief = "Pressure Drop", DisplayUnit = 'kPa', Symbol ="\Delta P", Protected=true);
239        Peq                     as pressure             (Brief="Equilibrium pressure on the liquid surface", Protected=true, Symbol="\Delta P_{eq}");
240        Pstatic         as pressure             (Brief="Static head at the bottom of the tank", Protected = true, Symbol="P_{static}^{Liquid}");
241
242out     TI as control_signal    (Brief="Temperature Indicator", PosX=0.525, PosY=0, Protected=true);
243out     PI as control_signal    (Brief="Pressure Indicator", PosX=0.368, PosY=0, Protected=true);
244out     LI as control_signal    (Brief="Level Indicator", PosX=1, PosY=0.6, Protected=true);
245
246INITIAL
247
248"Initial level Percent"
249        LI = Levelpercent_Initial;
250       
251"Initial Outlet Liquid Temperature"
252        OutletLiquid.T = Temperature_Initial;
253       
254"Initial Outlet Liquid Composition Normalized"
255        OutletLiquid.z(1:NComp - 1) = Composition_Initial(1:NComp - 1)/sum(Composition_Initial);
256
257EQUATIONS
258
[831]259switch NormalFlow
260
261case "on":
262        Inlet.F = Kfactor *sqrt(Pdrop)*KfConst;
263
264        when Inlet.F < low_flow switchto "off";
265
266case "off":
267        Inlet.F = zero_flow;
268
269        when Inlet.P > OutletVapour.P switchto "on";
270
271end
272
[795]273"Component Molar Balance"
274        diff(TotalHoldup)=Inlet.F*Inlet.z - OutletLiquid.F*OutletLiquid.z - OutletVapour.F*OutletVapour.z;
[794]275       
[795]276"Energy Balance"
277        diff(E) = Inlet.F*Inlet.h - OutletLiquid.F*OutletLiquid.h - OutletVapour.F*OutletVapour.h + InletQ;
[794]278       
[795]279"Molar Holdup"
280        TotalHoldup = LiquidHoldup*OutletLiquid.z + VapourHoldup*OutletVapour.z;
281       
[794]282"Energy Holdup"
[879]283        E = LiquidHoldup*OutletLiquid.h + VapourHoldup*OutletVapour.h - OutletLiquid.P*Geometry.Vtotal;
[794]284       
[795]285"Mol fraction normalisation"
286        sum(OutletLiquid.z)=1.0;
287
288"Mol fraction normalisation"
289        sum(OutletLiquid.z)=sum(OutletVapour.z);
290
[794]291"Liquid Volume"
[831]292        vL = PP.LiquidVolume(OutletLiquid.T, Peq, OutletLiquid.z);
[795]293
294"Vapour Volume"
[831]295        vV = PP.VapourVolume(OutletVapour.T, Peq, OutletVapour.z);
[794]296       
[795]297"Chemical Equilibrium"
[831]298        PP.LiquidFugacityCoefficient(OutletLiquid.T, Peq, OutletLiquid.z)*OutletLiquid.z =
299                PP.VapourFugacityCoefficient(OutletVapour.T, Peq, OutletVapour.z)*OutletVapour.z;
[794]300       
[795]301"Thermal Equilibrium"
302        OutletVapour.T = OutletLiquid.T;
303       
304"Mechanical Equilibrium"
[831]305        OutletVapour.P = Peq;
[794]306
[831]307"Static Head"   
[879]308        Pstatic = PP.LiquidDensity(OutletLiquid.T, Peq, OutletLiquid.z) * Gconst * Geometry.Level;
[831]309
310"Mechanical Equilibrium for the Liquid Phase"
311        OutletLiquid.P = Peq + Pstatic;
312
[795]313"Pressure Drop"
[831]314        Pdrop = Inlet.P - OutletVapour.P;
[794]315
[795]316"Geometry Constraint"
[879]317        Geometry.Vtotal = LiquidHoldup * vL + VapourHoldup * vV;
[795]318
319"Temperature indicator"
320        TI * 'K' = OutletLiquid.T;
321
322"Pressure indicator"
323        PI * 'atm' = OutletLiquid.P;
324
325"Level indicator"
[879]326        LI*Geometry.Vtotal= Geometry.Vfilled;
[795]327
328"Liquid Level"
[879]329        LiquidHoldup * vL = Geometry.Vfilled;
[795]330
[794]331end
332
[799]333Model TankL
334
335ATTRIBUTES
[270]336        Pallete         = true;
[799]337        Icon            = "icon/TankL";
338        Brief           = "Model of a Tank.";
[270]339        Info            =
[799]340"== ASSUMPTIONS ==
341* liquid phase only;
342
343== SET ==
344*Orientation: vessel position - vertical or horizontal;
345*Heads (bottom and top heads are identical)
346**elliptical: 2:1 elliptical heads (25% of vessel diameter);
347**hemispherical: hemispherical heads (50% of vessel diameter);
348**flat: flat heads (0% of vessel diameter);
349*Diameter: Vessel diameter;
350*Lenght: Side length of the cylinder shell;
351       
352== SPECIFY ==
[353]353* the Inlet stream;
[799]354* the OutletLiquid.F;
355* the InletQ (the model requires an energy stream, also you can use a controller for setting the heat duty using the heat_flow model).
[1]356
[799]357== OPTIONAL ==
358* the TankL model has three control ports
359** TI OutletLiquid Temperature Indicator;
360** PI OutletLiquid Pressure Indicator;
361** LI Level Indicator;
362
363== INITIAL CONDITIONS ==
364* Initial_Temperature :  the Tank temperature (OutletLiquid.T);
[821]365* Levelpercent_Initial : the Tank liquid level in percent (LI);
[799]366* Initial_Composition : (NoComps) OutletLiquid compositions.
[353]367";
[270]368       
[649]369PARAMETERS
[799]370outer PP                as Plugin       (Brief = "External Physical Properties", Type="PP");
371outer NComp     as Integer      (Brief = "Number of components", Lower = 1);
372
[879]373        Gconst                  as acceleration (Brief="Gravity Acceleration",Default=9.81,Hidden=true);
[831]374        low_flow        as flow_mol     (Brief = "Low Flow",Default = 1E-6, Hidden=true);
375        zero_flow       as flow_mol     (Brief = "No Flow",Default = 0, Hidden=true);
376        KfConst         as Real                 (Brief="Constant for K factor pressure drop", Unit= 'mol/(s*(Pa^0.5))',Default = 1, Hidden=true);
377        Kfactor as positive (Brief="K factor for pressure drop", Lower = 1E-8, Default = 2);
378       
379        NormalFlow      as Switcher     (Brief="Normal Flow", Valid = ["on", "off"], Default = "on",Hidden=true);
380
381
[799]382        Levelpercent_Initial                    as positive     (Brief="Initial liquid height in Percent", Default = 0.70);
383        Temperature_Initial                             as temperature  (Brief="Initial Liquid Temperature", Default = 330);
384        Composition_Initial(NComp)              as fraction             (Brief="Initial Composition", Default = 0.10);
[781]385
386SET
387
[879]388        Gconst = 9.81 * 'm/(s^2)';
[831]389        low_flow = 1E-6 * 'kmol/h';
390        zero_flow = 0 * 'kmol/h';
391        KfConst = 1*'mol/(s*(Pa^0.5))';
[799]392
[649]393VARIABLES
[1]394
[879]395        Geometry                as VesselVolume (Brief="Vessel Geometry", Symbol=" ");
396
[799]397in      Inlet                   as stream                       (Brief="Feed Stream", PosX=0.22, PosY=0, Symbol="_{in}");
398out     OutletLiquid    as liquid_stream        (Brief="Liquid outlet stream", PosX=0.43, PosY=1, Symbol="_{out}^{Liquid}");
399in      InletQ                  as power                        (Brief="Heat Duty", PosX=0.735, PosY=1, Protected =true,Symbol="Q_{in}");
[721]400
[799]401        TotalHoldup(NComp)              as mol  (Brief="Molar Holdup in the Vessel", Protected=true);
402       
403        E                       as energy               (Brief="Total Energy Holdup in the Vessel", Protected=true);
404        vL                      as volume_mol   (Brief="Liquid Molar Volume", Protected=true);
[828]405        Pstatic         as pressure             (Brief="Static head at the bottom of the tank", Protected = true, Symbol="P_{static}^{Liquid}");
406
[799]407out     TI as control_signal    (Brief="Temperature Indicator", PosX=0.525, PosY=0, Protected=true);
408out     PI as control_signal    (Brief="Pressure Indicator", PosX=0.368, PosY=0, Protected=true);
409out     LI as control_signal    (Brief="Level Indicator", PosX=1, PosY=0.6, Protected=true);
[782]410
[799]411INITIAL
[649]412
[799]413"Initial level Percent"
414        LI = Levelpercent_Initial;
[782]415       
[799]416"Initial Outlet Liquid Temperature"
417        OutletLiquid.T = Temperature_Initial;
[1]418       
[799]419"Initial Outlet Liquid Composition Normalized"
420        OutletLiquid.z(1:NComp - 1) = Composition_Initial(1:NComp - 1)/sum(Composition_Initial);
[1]421
[799]422EQUATIONS
423
[831]424#*
425switch NormalFlow
426
427case "on":
428        Inlet.F = Kfactor *sqrt(Pstatic)*KfConst;
429
430        when Inlet.F < low_flow switchto "off";
431
432case "off":
433        Inlet.F = zero_flow;
434
435        when Inlet.P > OutletLiquid.P switchto "on";
436
437end
438*#
[799]439"Component Molar Balance"
440        diff(TotalHoldup)=Inlet.F*Inlet.z - OutletLiquid.F*OutletLiquid.z;
441       
442"Energy Balance"
443        diff(E) = Inlet.F*Inlet.h - OutletLiquid.F*OutletLiquid.h + InletQ;
444
[649]445"Energy Holdup"
[799]446        E = sum(TotalHoldup)*OutletLiquid.h;
447
[828]448"Static Head"   
[879]449        Pstatic = PP.LiquidDensity(OutletLiquid.T, Inlet.P, OutletLiquid.z) * Gconst * Geometry.Level;
[828]450
[649]451"Mechanical Equilibrium"
[828]452        Inlet.P + Pstatic = OutletLiquid.P;
[799]453
[649]454"Liquid Volume"
[799]455        vL = PP.LiquidVolume(OutletLiquid.T, OutletLiquid.P, OutletLiquid.z);
456
457"Molar Holdup"
458        TotalHoldup = OutletLiquid.z*sum(TotalHoldup);
[1]459       
[799]460"Liquid Level"
[879]461        Geometry.Vfilled = sum(TotalHoldup) * vL;
[1]462       
[799]463"Temperature indicator"
464        TI * 'K' = OutletLiquid.T;
[1]465
[799]466"Pressure indicator"
467        PI * 'atm' = OutletLiquid.P;
[649]468
[799]469"Level indicator"
[879]470        LI*Geometry.Vtotal= Geometry.Vfilled;
[781]471
[1]472end
473
[800]474Model SumpTank
475
476ATTRIBUTES
477        Pallete         = true;
478        Icon            = "icon/SumpTank";
[820]479        Brief           = "Model of a tank with 2 material inlet streams and with thermodynamic equilibrium.";
[800]480        Info            =
481"== ASSUMPTIONS ==
[805]482* perfect mixing of both phases;
483* thermodynamics equilibrium.
[800]484
485== SET ==
[805]486*Orientation: vessel position - vertical or horizontal;
487*Heads (bottom and top heads are identical)
488**elliptical: 2:1 elliptical heads (25% of vessel diameter);
489**hemispherical: hemispherical heads (50% of vessel diameter);
490**flat: flat heads (0% of vessel diameter);
[800]491*Diameter: Vessel diameter;
492*Lenght: Side length of the cylinder shell;
493       
494== SPECIFY ==
495* the Inlet stream;
[805]496* the outlet flows: OutletVapour.F and OutletLiquid.F;
497* the InletQ (the model requires an energy stream, also you can use a controller for setting the heat duty using the heat_flow model).
[800]498
499== OPTIONAL ==
[821]500* the SumpTank model has three control ports
[805]501** TI OutletLiquid Temperature Indicator;
502** PI OutletLiquid Pressure Indicator;
[800]503** LI Level Indicator;
504
505== INITIAL CONDITIONS ==
506* Initial_Temperature :  the Tank temperature (OutletLiquid.T);
[821]507* Levelpercent_Initial : the Tank liquid level in percent (LI);
[800]508* Initial_Composition : (NoComps) OutletLiquid compositions.
509";
510       
511PARAMETERS
512outer PP                as Plugin       (Brief = "External Physical Properties", Type="PP");
513outer NComp     as Integer      (Brief = "Number of components", Lower = 1);
514
[805]515        Mw(NComp)               as molweight    (Brief="Mol Weight", Hidden=true);
[800]516        pi                      as positive             (Brief="Pi value", Default=3.141593,Hidden=true, Symbol="\pi");
[820]517        g                               as acceleration         (Brief="Gravity Acceleration",Default=9.81,Hidden=true);
[805]518       
519        Heads                   as Switcher     (Valid=["elliptical","hemispherical","flat"],Default="flat");
[800]520        Diameter                as length               (Brief="Vessel diameter", Symbol="D_{i}");
521        Lenght                  as length               (Brief="Side length of the cylinder shell", Symbol="L_{vessel}");
522       
523        Vhead_elliptical                as volume               (Brief="Elliptical Head Total Volume",Hidden=true, Symbol="V_{head}^{elliptical}");
524        Vhead_hemispherical     as volume               (Brief="Hemispherical Head Total Volume",Hidden=true, Symbol="V_{head}^{hemispherical}");
525        Vcylinder                               as volume               (Brief="Cylinder Total Volume",Hidden=true, Symbol="V_{cylinder}");
526        radius                                  as length               (Brief="Vessel radius",Hidden=true, Symbol="R_{cylinder}");
527       
528        Levelpercent_Initial                    as positive     (Brief="Initial liquid height in Percent", Default = 0.70);
529        Temperature_Initial                             as temperature  (Brief="Initial Liquid Temperature", Default = 330);
530        Composition_Initial(NComp)              as fraction             (Brief="Initial Composition", Default = 0.10);
531
532SET
533
[805]534        Mw=PP.MolecularWeight();
535
[820]536        g = 9.81 * 'm/(s^2)';
[805]537        Vhead_elliptical        = (pi*Diameter^3)/12;
538        Vhead_hemispherical = (pi*Diameter^3)/6;
[800]539        Vcylinder = 0.25*(pi*Diameter^2)*Lenght;
540        radius = 0.5*Diameter;
541
542VARIABLES
543
[805]544in      InletLiquid     as stream                       (Brief="Feed Stream", PosX=0.22, PosY=0, Symbol="_{in}");
545out     OutletLiquid    as liquid_stream        (Brief="Liquid outlet stream", PosX=0.50, PosY=1, Symbol="_{out}^{Liquid}");
546in      InletVapour     as stream                       (Brief="Vapour outlet stream", PosX=1, PosY=0.20, Symbol="_{out}^{Vapour}");
547out     OutletVapour    as vapour_stream        (Brief="Vapour outlet stream", PosX=0.68, PosY=0, Symbol="_{out}^{Vapour}");
548        InletQ                  as power                        (Brief="Heat Duty", Protected =false,Symbol="Q_{in}");
[800]549
550        Vtotal                  as volume                       (Brief="Vessel total volume",Protected=true, Symbol="V_{total}");
551        Vfilled                 as volume                       (Brief="Vessel volume content",Protected=true, Symbol="V_{filled}");
552
553        TotalHoldup(NComp)              as mol  (Brief="Molar Holdup in the Vessel", Protected=true);
[805]554        LiquidHoldup                    as mol  (Brief="Molar liquid holdup", Protected=true);
555        VapourHoldup                    as mol  (Brief="Molar vapour holdup", Protected=true);
[800]556       
557        E                       as energy               (Brief="Total Energy Holdup in the Vessel", Protected=true);
558        vL                      as volume_mol   (Brief="Liquid Molar Volume", Protected=true);
[805]559        vV                      as volume_mol   (Brief="Vapour Molar volume", Protected=true);
[800]560        Level           as length               (Brief="liquid height", Protected=true);
561        Across          as area                 (Brief="Vessel cylinder shell Cross section area", Hidden=true, Symbol="A_{cross}");
[826]562        #Pdrop          as press_delta  (Brief = "Pressure Drop", DisplayUnit = 'kPa', Symbol ="\Delta P", Protected=true);
[800]563
[825]564        Peq             as pressure             (Brief="Equilibrium pressure on the liquid surface", Protected=true, Symbol="P_{eq}");
565        Pstatic         as pressure             (Brief="Static head at the bottom of the tank", Protected = true, Symbol="P_{static}^{Liquid}");
[820]566
[807]567out     LI as control_signal    (Brief="Level Indicator", PosX=1, PosY=0.7, Protected=true);
568out     TI as control_signal    (Brief="Temperature Indicator", PosX=1, PosY=0.6, Protected=true);
[800]569
570INITIAL
571
572"Initial level Percent"
573        LI = Levelpercent_Initial;
574       
575"Initial Outlet Liquid Temperature"
576        OutletLiquid.T = Temperature_Initial;
577       
578"Initial Outlet Liquid Composition Normalized"
579        OutletLiquid.z(1:NComp - 1) = Composition_Initial(1:NComp - 1)/sum(Composition_Initial);
580
581EQUATIONS
582
583"Vessel Cross Section Area"
584        Across = 0.25*(pi*Diameter^2);
585
[805]586switch Heads
[800]587
588case "elliptical":
589
590"Vessel Total Volume"
591        Vtotal = Vhead_elliptical +     Vcylinder;
592
593if Level < 0.25*Diameter then
594
595"Vessel Filled Volume"
596        Vfilled = 0.25*pi*(((Diameter*Level)/(0.25*Diameter))^2)*(0.25*Diameter-Level/3);
597
598else
599
600"Vessel Filled Volume"
601        Vfilled = 0.25*pi*(Diameter^2)*(Level - 0.25*Diameter/3);
602
603end
604
605case "hemispherical":
606
607"Vessel Total Volume"
608        Vtotal = Vhead_hemispherical + Vcylinder;
609
610if Level < 0.5*Diameter then
611
612"Vessel Filled Volume"
613        Vfilled = 0.25*pi*(Level^2)*(2*Diameter-4*Level/3);
614
615else
616
617"Vessel Filled Volume"
618        Vfilled = 0.25*pi*((2/3)*((0.5*Diameter)^3) - (0.25*(Diameter)^3) + Level*Diameter^2);
619
620end
621
622case "flat":
623
624"Vessel Total Volume"
625        Vtotal = Vcylinder;
626
627"Vessel Filled Volume"
628        Vfilled = Across*Level;
629
630end
631
632"Component Molar Balance"
[805]633        diff(TotalHoldup) = InletLiquid.F*InletLiquid.z + InletVapour.F*InletVapour.z- OutletLiquid.F*OutletLiquid.z - OutletVapour.F*OutletVapour.z;
[800]634       
635"Energy Balance"
[805]636        diff(E) = InletLiquid.F*InletLiquid.h + InletVapour.F*InletVapour.h - OutletLiquid.F*OutletLiquid.h - OutletVapour.F*OutletVapour.h + InletQ;
637       
638"Molar Holdup"
639        TotalHoldup = LiquidHoldup*OutletLiquid.z + VapourHoldup*OutletVapour.z;
640       
[800]641"Energy Holdup"
[805]642        E = LiquidHoldup*OutletLiquid.h + VapourHoldup*OutletVapour.h - OutletLiquid.P*Vtotal;
643       
644"Mol fraction normalisation"
645        sum(OutletLiquid.z)=1.0;
[800]646
[805]647"Mol fraction normalisation"
648        sum(OutletLiquid.z)=sum(OutletVapour.z);
[800]649
650"Liquid Volume"
[820]651        vL = PP.LiquidVolume(OutletLiquid.T, Peq, OutletLiquid.z);
[800]652
[805]653"Vapour Volume"
[820]654        vV = PP.VapourVolume(OutletVapour.T, Peq, OutletVapour.z);
[800]655       
[805]656"Chemical Equilibrium"
[820]657        PP.LiquidFugacityCoefficient(OutletLiquid.T, Peq, OutletLiquid.z)*OutletLiquid.z =
658                PP.VapourFugacityCoefficient(OutletVapour.T, Peq, OutletVapour.z)*OutletVapour.z;
[800]659       
[805]660"Thermal Equilibrium"
661        OutletVapour.T = OutletLiquid.T;
662       
[820]663"Mechanical Equilibrium for the Vapour Phase"
664        OutletVapour.P = Peq;
665       
666"Static Head"   
667        Pstatic = PP.LiquidDensity(OutletLiquid.T, Peq, OutletLiquid.z) * g * Level;
[805]668
[820]669"Mechanical Equilibrium for the Liquid Phase"
670        OutletLiquid.P = Peq + Pstatic;
671
[826]672#*"Pressure Drop"
[820]673        Pdrop = min([InletLiquid.P,InletVapour.P]) - OutletLiquid.P;
674        #OutletLiquid.P  = InletLiquid.P - Pdrop;
[826]675*#
[805]676
677"Geometry Constraint"
678        Vtotal = LiquidHoldup * vL + VapourHoldup * vV;
679
[800]680"Level indicator"
681        LI*Vtotal= Vfilled;
682
[807]683"Temperature indicator"
[834]684        TI * 'K' = OutletVapour.T;
[807]685
[805]686"Liquid Level"
687        LiquidHoldup * vL = Vfilled;
688
[800]689end
690
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