#*-------------------------------------------------------------------
* 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.
*
*
*---------------------------------------------------------------------
* Model of a Multistream Heat Exchanger
*
*	Streams:
*		* Hot Inlet streams .... 	at least one Hot material stream
*		* Cold Inlet streams .... 	at least one Cold material stream
*		* Hot Outlet streams  ....	one material stream for each Hot Inlet
*		* Cold Outlet streams  ....	one material stream for each Cold Inlet
*
*	Purpose:
*		* Heat Transfer between multiple hot and cold streams.
*
*----------------------------------------------------------------------
* Author: Gerson Balbueno Bicca 
* $Id: Mheatex.mso 122 2007-01-18 16:06:09Z bicca $
*--------------------------------------------------------------------*#

using "streams.mso";

Model Inlet_Main_Stream 	
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++#
# 	Inlet Streams
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++#
PARAMETERS

	Ncold   as Integer	(Brief="Number of Inlet Cold Streams",Lower=1);
	Nhot    as Integer	(Brief="Number of Inlet Hot Streams",Lower=1);
	
VARIABLES

	Hot  (Nhot) 	as stream;# Inlet Hot Streams
	Cold (Ncold) 	as stream;# Inlet Cold Streams
	
end

Model Outlet_Main_Stream 	
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++#
# 	Outlet Streams
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++#
PARAMETERS

	Ncold   as Integer	(Brief="Number of Inlet Cold Streams",Lower=1);
	Nhot    as Integer	(Brief="Number of Inlet Hot Streams",Lower=1);
	
VARIABLES

	Hot  (Nhot) 	as stream_therm;# Outlet Hot Streams
	Cold (Ncold) 	as stream_therm;# Outlet Cold Streams
	
end

Model Mheatex
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++#
# 	Multistream Heat Exchanger Basic Calculation
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++#
PARAMETERS

ext PP 		as CalcObject	(Brief="Physical Properties");
ext	NComp   as Integer 		(Brief="Number of Components");	
	HE 		as CalcObject 	(Brief="Cold Box Calculations",File="heatex");
	Side	as Integer		(Brief="Flow Direction",Lower=0,Upper=1);
	Ncold   as Integer		(Brief="Number of Inlet Cold Streams",Lower=1);
	Nhot    as Integer		(Brief="Number of Inlet Hot Streams",Lower=1);
	
VARIABLES

in  Inlet  	as Inlet_Main_Stream;		# Inlet Hot Streams
out Outlet 	as Outlet_Main_Stream;		# Outlet Hot Streams

	Q    	as power		(Brief="Heat Transfer");
	LMTD	as temp_delta	(Brief="Logarithmic Mean Temperature Difference");
	UA      as positive     (Unit="W/K");
	DT0     as temp_delta	(Brief="Temperature Difference at Inlet",Lower=1);
	DTL		as temp_delta	(Brief="Temperature Difference at Outlet",Lower=1);
	
SET

# Flow Direction
	Side = HE.FlowDir();

# Inlet Ncold Parameters
	Inlet.Ncold  = Ncold;
	
# Outlet Ncold Parameters
	Outlet.Ncold = Ncold;

# Inlet Nhot Parameters
	Inlet.Nhot  = Nhot;
	
# Outlet Nhot Parameters
	Outlet.Nhot = Nhot ;

EQUATIONS

"Hot Flow"
	Outlet.Hot.F = Inlet.Hot.F;	

"Cold Flow"
	Outlet.Cold.F = Inlet.Cold.F;
	
"Hot Composition"
	Outlet.Hot.z = Inlet.Hot.z;
	
"Cold Composition"
	Outlet.Cold.z = Inlet.Cold.z;
	


for i in [1:Nhot]

"Vapourisation Fraction Hot Stream"
	Outlet.Hot(i).v = PP.VapourFraction(Outlet.Hot(i).T,Outlet.Hot(i).P,Outlet.Hot(i).z);		
	
end	


for j in [1:Ncold]
	
"Vapourisation Fraction Cold Stream"
	Outlet.Cold(j).v = PP.VapourFraction(Outlet.Cold(j).T,Outlet.Cold(j).P,Outlet.Cold(j).z);
	
end
	

"Heat Duty Hot Stream"
	Q =  sum(Inlet.Hot.F*(Inlet.Hot.h- Outlet.Hot.h));
	
"Heat Duty Cold Stream"
	Q = -sum(Inlet.Cold.F*(Inlet.Cold.h- Outlet.Cold.h));
	
"Heat Duty"
	Q=UA*LMTD;

	
if abs(DT0 - DTL) > 0.05*max(abs([DT0,DTL])) 
	
	then
"Log Mean Temperature Difference"
	LMTD= (DT0-DTL)/ln(DT0/DTL);

	else
	
if DT0*DTL equal 0
	
	then
"Log Mean Temperature Difference"
	LMTD = 0.5*(DT0+DTL);
	
	else
"Log Mean Temperature Difference"
	LMTD = 0.5*(DT0+DTL)*(1-(DT0-DTL)^2/(DT0*DTL)*(1+(DT0-DTL)^2/(DT0*DTL)/2)/12);
	
end
	
end	


if Side equal 0 
	
	then
	
"Temperature Difference at Inlet"
	DT0 = max(Inlet.Hot.T) - min(Inlet.Cold.T);

"Temperature Difference at Outlet"
	DTL = min(Outlet.Hot.T) - max(Outlet.Cold.T);
	
	else
	
"Temperature Difference at Inlet"
	DT0 = max(Inlet.Hot.T) - max(Outlet.Cold.T);

"Temperature Difference at Outlet"
	DTL = min(Outlet.Hot.T) - min(Inlet.Cold.T);
	
end

end