#*------------------------------------------------------------------- * EMSO Model Library (EML) Copyright (C) 2004 - 2007 ALSOC. * * This LIBRARY is free software; you can distribute it and/or modify * it under the therms of the ALSOC FREE LICENSE as available at * http://www.enq.ufrgs.br/alsoc. * * EMSO Copyright (C) 2004 - 2007 ALSOC, original code * from http://www.rps.eng.br Copyright (C) 2002-2004. * All rights reserved. * * EMSO is distributed under the therms of the ALSOC LICENSE as * available at http://www.enq.ufrgs.br/alsoc. * *---------------------------------------------------------------------- * Author: Paula B. Staudt * $Id: reboiler.mso 353 2007-08-30 16:12:27Z arge $ *--------------------------------------------------------------------*# using "streams"; Model reboiler ATTRIBUTES Pallete = true; Icon = "icon/Reboiler"; Brief = "Model of a dynamic reboiler - kettle."; Info = "== Assumptions == * perfect mixing of both phases; * thermodynamics equilibrium; * no liquid entrainment in the vapour stream. == Specify == * the inlet stream; * the liquid inlet stream; * the outlet flows: OutletV.F and OutletL.F; * the heat supply. == Initial Conditions == * the reboiler temperature (OutletL.T); * the reboiler liquid level (Level); * (NoComps - 1) OutletL (OR OutletV) compositions. "; PARAMETERS outer PP as Plugin(Brief = "External Physical Properties", Type="PP"); outer NComp as Integer; Across as area (Brief="Cross Section Area of reboiler"); V as volume (Brief="Total volume of reboiler"); VARIABLES in Inlet as stream(Brief="Feed Stream", PosX=0.8127, PosY=0, Symbol="_{in}"); in InletL as stream(Brief="Liquid inlet stream", PosX=0, PosY=0.5254, Symbol="_{inL}"); out OutletL as liquid_stream(Brief="Liquid outlet stream", PosX=0.2413, PosY=1, Symbol="_{outL}"); out OutletV as vapour_stream(Brief="Vapour outlet stream", PosX=0.5079, PosY=0, Symbol="_{outV}"); in InletQ as energy_stream (Brief="Heat supplied", PosX=1, PosY=0.6123, Symbol="_{in}"); M(NComp) as mol (Brief="Molar Holdup in the tray"); ML as mol (Brief="Molar liquid holdup"); MV as mol (Brief="Molar vapour holdup"); E as energy (Brief="Total Energy Holdup on tray"); vL as volume_mol (Brief="Liquid Molar Volume"); vV as volume_mol (Brief="Vapour Molar volume"); Level as length (Brief="Level of liquid phase"); rhoV as dens_mass (Brief="Vapour Density"); EQUATIONS "Component Molar Balance" diff(M)= Inlet.F*Inlet.z + InletL.F*InletL.z - OutletL.F*OutletL.z - OutletV.F*OutletV.z; "Energy Balance" diff(E) = Inlet.F*Inlet.h + InletL.F*InletL.h - OutletL.F*OutletL.h - OutletV.F*OutletV.h + InletQ.Q; "Molar Holdup" M = ML*OutletL.z + MV*OutletV.z; "Energy Holdup" E = ML*OutletL.h + MV*OutletV.h - OutletL.P*V; "Mol fraction normalisation" sum(OutletL.z)=1.0; sum(OutletL.z)=sum(OutletV.z); "Vapour Density" rhoV = PP.VapourDensity(OutletV.T, OutletV.P, OutletV.z); "Liquid Volume" vL = PP.LiquidVolume(OutletL.T, OutletL.P, OutletL.z); "Vapour Volume" vV = PP.VapourVolume(OutletV.T, OutletV.P, OutletV.z); "Chemical Equilibrium" PP.LiquidFugacityCoefficient(OutletL.T, OutletL.P, OutletL.z)*OutletL.z = PP.VapourFugacityCoefficient(OutletV.T, OutletV.P, OutletV.z)*OutletV.z; "Mechanical Equilibrium" OutletL.P = OutletV.P; "Thermal Equilibrium" OutletL.T = OutletV.T; "Geometry Constraint" V = ML*vL + MV*vV; "Level of liquid phase" Level = ML*vL/Across; end #*---------------------------------------------------------------------- * Model of a Steady State reboiler with no thermodynamics equilibrium *---------------------------------------------------------------------*# Model reboilerSteady ATTRIBUTES Pallete = true; Icon = "icon/ReboilerSteady"; Brief = "Model of a Steady State reboiler with no thermodynamics equilibrium - thermosyphon."; Info = "== Assumptions == * perfect mixing of both phases; * no thermodynamics equilibrium; * no liquid entrainment in the vapour stream. == Specify == * the InletL stream; * the heat supply OR the outlet temperature (OutletV.T); "; PARAMETERS outer PP as Plugin(Brief = "External Physical Properties", Type="PP"); outer NComp as Integer; DP as press_delta (Brief="Pressure Drop in the reboiler"); VARIABLES in InletL as stream(Brief="Liquid inlet stream", PosX=0.3345, PosY=1, Symbol="_{inL}"); out OutletV as vapour_stream(Brief="Vapour outlet stream", PosX=0.3369, PosY=0, Symbol="_{outV}"); in InletQ as energy_stream (Brief="Heat supplied", PosX=1, PosY=0.6111, Symbol="_{in}"); vV as volume_mol (Brief="Vapour Molar volume"); rhoV as dens_mass (Brief="Vapour Density"); EQUATIONS "Molar Balance" InletL.F = OutletV.F; InletL.z = OutletV.z; "Vapour Volume" vV = PP.VapourVolume(OutletV.T, OutletV.P, OutletV.z); "Vapour Density" rhoV = PP.VapourDensity(OutletV.T, OutletV.P, OutletV.z); "Energy Balance" InletL.F*InletL.h + InletQ.Q = OutletV.F*OutletV.h; "Pressure" DP = InletL.P - OutletV.P; end #*---------------------------------------------------------------------- * Model of a Steady State reboiler with fake calculation of * vaporisation fraction and output temperature, but with a real * calculation of the output stream enthalpy *---------------------------------------------------------------------*# Model reboilerSteady_fakeH ATTRIBUTES Pallete = true; Icon = "icon/ReboilerSteady"; Brief = "Model of a Steady State reboiler with fake calculation of outlet conditions."; Info = "Model of a Steady State reboiler with fake calculation of vaporisation fraction and output temperature, but with a real calculation of the output stream enthalpy. "; PARAMETERS outer PP as Plugin(Brief = "External Physical Properties", Type="PP"); outer NComp as Integer; DP as press_delta (Brief="Pressure Drop in the reboiler"); k as Real (Brief = "Flow Constant", Unit='mol/J'); VARIABLES in InletL as stream(Brief="Liquid inlet stream", PosX=0.3345, PosY=1, Symbol="_{inL}"); out OutletV as vapour_stream(Brief="Vapour outlet stream", PosX=0.3369, PosY=0, Symbol="_{outV}"); in InletQ as energy_stream (Brief="Heat supplied", PosX=1, PosY=0.6111, Symbol="_{in}"); EQUATIONS "Molar Balance" InletL.F = OutletV.F; InletL.z = OutletV.z; "Energy Balance" InletL.F*InletL.h + InletQ.Q = OutletV.F*OutletV.h; "Pressure" DP = InletL.P - OutletV.P; "Fake Vapourisation Fraction" OutletV.v = 1.0; "Fake output temperature" OutletV.T = 300*'K'; "Pressure Drop through the reboiler" OutletV.F = k*InletQ.Q; end #*------------------------------------------------------------------- * Model of a dynamic reboiler with reaction *-------------------------------------------------------------------*# Model reboilerReact ATTRIBUTES Pallete = true; Icon = "icon/Reboiler"; Brief = "Model of a dynamic reboiler with reaction."; Info = "== Assumptions == * perfect mixing of both phases; * thermodynamics equilibrium; * no liquid entrainment in the vapour stream; * the reaction takes place only in the liquid phase. == Specify == * the kinetics variables; * the inlet stream; * the liquid inlet stream; * the outlet flows: OutletV.F and OutletL.F; * the heat supply. == Initial Conditions == * the reboiler temperature (OutletL.T); * the reboiler liquid level (Level); * (NoComps - 1) OutletL (OR OutletV) compositions. "; PARAMETERS outer PP as Plugin(Type="PP"); outer NComp as Integer; Across as area (Brief="Cross Section Area of reboiler"); V as volume (Brief="Total volume of reboiler"); stoic(NComp) as Real(Brief="Stoichiometric matrix"); Hr as energy_mol; Pstartup as pressure; VARIABLES in Inlet as stream(Brief="Feed Stream", PosX=0.8127, PosY=0, Symbol="_{in}"); in InletL as stream(Brief="Liquid inlet stream", PosX=0, PosY=0.5254, Symbol="_{inL}"); out OutletL as liquid_stream(Brief="Liquid outlet stream", PosX=0.2413, PosY=1, Symbol="_{outL}"); out OutletV as vapour_stream(Brief="Vapour outlet stream", PosX=0.5079, PosY=0, Symbol="_{outV}"); in InletQ as energy_stream (Brief="Heat supplied", PosX=1, PosY=0.6123, Symbol="_{in}"); M(NComp) as mol (Brief="Molar Holdup in the tray"); ML as mol (Brief="Molar liquid holdup"); MV as mol (Brief="Molar vapour holdup"); E as energy (Brief="Total Energy Holdup on tray"); vL as volume_mol (Brief="Liquid Molar Volume"); vV as volume_mol (Brief="Vapour Molar volume"); Level as length (Brief="Level of liquid phase"); Vol as volume; startup as Real; rhoV as dens_mass; r3 as reaction_mol (Brief = "Reaction resulting ethyl acetate", DisplayUnit = 'mol/l/s'); C(NComp) as conc_mol (Brief = "Molar concentration", Lower = -1); EQUATIONS "Molar Concentration" OutletL.z = vL * C; "Reaction" r3 = exp(-7150*'K'/OutletL.T)*(4.85e4*C(1)*C(2) - 1.23e4*C(3)*C(4)) * 'l/mol/s'; "Component Molar Balance" diff(M)= Inlet.F*Inlet.z + InletL.F*InletL.z - OutletL.F*OutletL.z - OutletV.F*OutletV.z + stoic*r3*ML*vL; "Energy Balance" diff(E) = Inlet.F*Inlet.h + InletL.F*InletL.h - OutletL.F*OutletL.h - OutletV.F*OutletV.h + InletQ.Q + Hr * r3 * vL*ML; "Molar Holdup" M = ML*OutletL.z + MV*OutletV.z; "Energy Holdup" E = ML*OutletL.h + MV*OutletV.h - OutletL.P*V; "Mol fraction normalisation" sum(OutletL.z)=1.0; "Liquid Volume" vL = PP.LiquidVolume(OutletL.T, OutletL.P, OutletL.z); "Vapour Volume" vV = PP.VapourVolume(OutletV.T, OutletV.P, OutletV.z); "Vapour Density" rhoV = PP.VapourDensity(OutletV.T, OutletV.P, OutletV.z); "Level of liquid phase" Level = ML*vL/Across; Vol = ML*vL; "Mechanical Equilibrium" OutletL.P = OutletV.P; "Thermal Equilibrium" OutletL.T = OutletV.T; "Geometry Constraint" V = ML*vL + MV*vV; "Chemical Equilibrium" PP.LiquidFugacityCoefficient(OutletL.T, OutletL.P, OutletL.z)*OutletL.z = PP.VapourFugacityCoefficient(OutletV.T, OutletV.P, OutletV.z)*OutletV.z; sum(OutletL.z)=sum(OutletV.z); end