#*-------------------------------------------------------------------
* 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: tray.mso 325 2007-07-29 00:41:04Z arge $
*--------------------------------------------------------------------*#

using "streams";

Model trayBasic
	ATTRIBUTES
	Pallete 	= false;
	Icon 		= "icon/Tray"; 
	Brief 		= "Basic equations of a tray column model.";
	Info 		=
	"This model contains only the main equations of a column tray equilibrium model without
	the hidraulic equations.
	
	Assumptions
	 * both phases (liquid and vapour) exists all the time;
	 * thermodymanic equilibrium with Murphree plate efficiency;
	 * no entrainment of liquid or vapour phase;
	 * no weeping;
	 * the dymanics in the downcomer are neglected.
	";
	
	PARAMETERS
outer PP as Plugin(Brief = "External Physical Properties", Type="PP");
outer NComp as Integer;
	V as volume(Brief="Total Volume of the tray");
	Q as heat_rate (Brief="Rate of heat supply"); 
	Ap as area (Brief="Plate area = Atray - Adowncomer");
	
	VARIABLES
in	Inlet as stream (Brief="Feed stream", PosX=0, PosY=0.4932);
in	InletL as stream (Brief="Inlet liquid stream", PosX=0.5195, PosY=0);
in	InletV as stream (Brief="Inlet vapour stream", PosX=0.4994, PosY=1);
out	OutletL as liquid_stream (Brief="Outlet liquid stream", PosX=0.8277, PosY=1);
out	OutletV as vapour_stream (Brief="Outlet vapour stream", PosX=0.8043, PosY=0);

	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="Height of clear liquid on plate");
	yideal(NComp) as fraction;
	Emv as Real (Brief = "Murphree efficiency");
	
	EQUATIONS
	"Component Molar Balance"
	diff(M)=Inlet.F*Inlet.z + InletL.F*InletL.z + InletV.F*InletV.z
		- OutletL.F*OutletL.z - OutletV.F*OutletV.z;
	
	"Energy Balance"
	diff(E) = ( Inlet.F*Inlet.h + InletL.F*InletL.h + InletV.F*InletV.h
		- OutletL.F*OutletL.h - OutletV.F*OutletV.h + 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);
	
	"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, yideal)*yideal;

	"Murphree Efficiency"
	OutletV.z = Emv * (yideal - InletV.z) + InletV.z;
	
	"Thermal Equilibrium"
	OutletV.T = OutletL.T;
	
	"Mechanical Equilibrium"
	OutletV.P = OutletL.P;
	
	"Geometry Constraint"
	V = ML* vL + MV*vV;
	
	"Level of clear liquid over the weir"
	Level = ML*vL/Ap;
end

Model tray as trayBasic
	ATTRIBUTES
	Pallete 	= false;
	Icon 		= "icon/Tray"; 
	Brief 		= "Complete 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 (OutletL.T)
	 * the liquid height (Level) OR the liquid flow OutletL.F
	 * (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");
	
	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);

	if Level > (beta * hw) then
		"Francis Equation"
		OutletL.F = 1.84*'1/s'*lw*((Level-(beta*hw))/(beta))^2/vL;
	else
		"Low level"
		OutletL.F = 0 * 'mol/h';
	end

end

#*-------------------------------------------------------------------
* Model of a tray with reaction
*-------------------------------------------------------------------*#
Model trayReact
	ATTRIBUTES
	Pallete 	= false;
	Icon 		= "icon/Tray"; 
	Brief 		= "Model of a tray with reaction.";
	Info 		=
	"Assumptions
	 * both phases (liquid and vapour) exists all the time;
	 * thermodymanic equilibrium with Murphree plate efficiency;
	 * no entrainment of liquid or vapour phase;
	 * no weeping;
	 * the dymanics in the downcomer are neglected.
	
	Specify:
	 * the Feed stream;
	 * the Liquid inlet stream;
	 * the Vapour inlet stream;
	 * the Vapour outlet flow (OutletV.F);
	 * the reaction related variables.
	
	Initial:
	 * the plate temperature (OutletL.T)
	 * the liquid height (Level) OR the liquid flow OutletL.F
	 * (NoComps - 1) OutletL compositions
	";

	PARAMETERS
	outer PP as Plugin(Type="PP");
	outer NComp as Integer;
	V as volume(Brief="Total Volume of the tray");
	Q as power (Brief="Rate of heat supply"); 
	Ap as area (Brief="Plate area = Atray - Adowncomer");
	
	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");

	stoic(NComp) as Real(Brief="Stoichiometric matrix");
	Hr as energy_mol;
	Pstartup as pressure;
	
	VapourFlow as Switcher(Valid = ["on", "off"], Default = "off");
	LiquidFlow as Switcher(Valid = ["on", "off"], Default = "off");
	
	VARIABLES
in	Inlet as stream (Brief="Feed stream", PosX=0, PosY=0.4932);
in	InletL as stream (Brief="Inlet liquid stream", PosX=0.5195, PosY=0);
in	InletV as stream (Brief="Inlet vapour stream", PosX=0.4994, PosY=1);
out	OutletL as liquid_stream (Brief="Outlet liquid stream", PosX=0.8277, PosY=1);
out	OutletV as vapour_stream (Brief="Outlet vapour stream", PosX=0.8043, PosY=0);

	yideal(NComp) as fraction;
	Emv as Real (Brief = "Murphree efficiency");

	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="Height of clear liquid on plate");
	Vol as volume;
	
	rhoL as dens_mass;
	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); #, Unit = "mol/l");
	
	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 + InletV.F*InletV.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 + InletV.F*InletV.h
		- OutletL.F*OutletL.h - OutletV.F*OutletV.h + 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);

	"Thermal Equilibrium"
	OutletV.T = OutletL.T;
	
	"Mechanical Equilibrium"
	OutletV.P = OutletL.P;
	
	"Level of clear liquid over the weir"
	Level = ML*vL/Ap;

	Vol = ML*vL;
	
	"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*'1/s'*lw*((Level-(beta*hw)+1e-6*'m')/(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.P = OutletV.P + Level*g*rhoL + rhoV*alfa*(InletV.F*vV/Ah)^2;
		InletV.F*vV = sqrt((InletV.P - OutletV.P - Level*g*rhoL + 1e-8 * 'atm')/(rhoV*alfa))*Ah;
		when InletV.P < OutletV.P + Level*g*rhoL switchto "off";
		
		case "off":
		InletV.F = 0 * 'mol/s';
		when InletV.P > OutletV.P + Level*g*rhoL + 3e-2 * 'atm' switchto "on";
		#when InletV.P > OutletV.P + Level*beta*g*rhoL + 1e-2 * 'atm' switchto "on";
	end

	"Chemical Equilibrium"
	PP.LiquidFugacityCoefficient(OutletL.T, OutletL.P, OutletL.z)*OutletL.z = 
		PP.VapourFugacityCoefficient(OutletV.T, OutletV.P, yideal)*yideal;
	
	OutletV.z = Emv * (yideal - InletV.z) + InletV.z;
	
	sum(OutletL.z)= sum(OutletV.z);
	
	"Geometry Constraint"
	V = ML* vL + MV*vV;
end