source: trunk/eml/heat_exchangers/Mheatex.mso @ 233

#*-------------------------------------------------------------------
* 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 197 2007-03-08 14:31:57Z bicca $
*--------------------------------------------------------------------*#

using "HEX_Engine.mso";

Model Mheatex
        
ATTRIBUTES
        Pallete = true;
        Brief = "Multistream heat exchangers";
        Info =
        "Heat Transfer between multiple hot and cold streams.";
        
PARAMETERS

outer PP                                        as Plugin       (Brief="Physical Properties", Type="PP");
outer   NComp                           as Integer      (Brief="Number of Components"); 
        FlowDirection                   as Switcher(Brief="Flow Direction",Valid=["counter","cocurrent"],Default="cocurrent");
        Ncold                                           as Integer      (Brief="Number of Inlet Cold Streams",Lower=1);
        Nhot                                            as Integer      (Brief="Number of Inlet Hot Streams",Lower=1);
        
VARIABLES

in      InletHot(Nhot)                  as stream               (Brief="Inlet Hot Streams");            
out     OutletHot(Nhot)                 as streamPH     (Brief="Outlet Hot Streams");
in      InletCold(Ncold)                as stream               (Brief="Inlet Cold Streams");           
out     OutletCold(Ncold)       as streamPH     (Brief="Outlet Cold Streams");

        Method  as LMTD_Basic   (Brief="Log Mean Temperature Difference Method");
        Q               as power                        (Brief="Heat Transfer", Default=7000, Lower=1e-6, Upper=1e10);
        UA              as Real                 (Brief="UA product",Unit='W/K',Lower=1e-8);
        
EQUATIONS

"Hot Flow"
        OutletHot.F = InletHot.F;       

"Cold Flow"
        OutletCold.F = InletCold.F;
        
"Hot Composition"
        OutletHot.z = InletHot.z;
        
"Cold Composition"
        OutletCold.z = InletCold.z;
        
"Heat Duty Hot Stream"
        Q =  sum(InletHot.F*(InletHot.h- OutletHot.h));
        
"Heat Duty Cold Stream"
        Q = -sum(InletCold.F*(InletCold.h- OutletCold.h));
        
"Heat Duty"
        Q = UA*Method.LMTD*Method.Fc;

switch FlowDirection
        
case    "cocurrent":

"Temperature Difference at Inlet"
        Method.DT0 = max(InletHot.T) - min(InletCold.T);

"Temperature Difference at Outlet"
        Method.DTL = min(OutletHot.T) - max(OutletCold.T);
        
case "counter":
        
"Temperature Difference at Inlet"
        Method.DT0 = max(InletHot.T) - max(OutletCold.T);

"Temperature Difference at Outlet"
        Method.DTL = min(OutletHot.T) - min(InletCold.T);
        
end

end