"!EES SIMULATION MODEL FOR THE PART LOAD BEHAVIOUR OF SINGLE STAGE H2O/LIBR ABSORPTION CHILLERS"
 
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%
% This work is supplementary material for the PHD-thesis:                 
%                                                                         
% Jan Albers: Erweiterung einer Berechnungsmethode für die Regelung von   
% Absorptionskälteanlagen (Enhancement of a calculation method for the 
% control of absorption chillers), TU Berlin, Fakultät III, 2019    
%  
% Copyright (C) 2019 by Jan Albers, TU Berlin, jan.albers@tu-berlin.de
%
%
% The computer code is licensed under GNU General Public License v2.0 
% (see https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html).                                                                        
%
% This program or library is free software; you can redistribute it and/or
% modify it under the terms of the GNU General Public License
% as published by the Free Software Foundation (version 2 only).
% 
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
% GNU General Public License for more details.
% 
% You should have received a copy of the GNU General Public License along
% with this program; if not, write to the Free Software Foundation, Inc., 
% 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
%                                                 
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ABSTRACT
This simulation model (i.e. the main file AKA_CE_Simulation.EES) calculates the partload behaviour of a single stage H2O/LiBr absorption chiller. For the characterisation of the chiller or heat pump only the heat transfer capabilities (i.e. the UA-values) of five heat exchangers (Desorber, Evaporator, Condenser, Absorber and Solution heat exchanger) and the pumped solution flow rate have to be known. Examplary values are provided in a supplementary library file (i.e. ZAKA_20190721ja.LIB). 
The heat transfer calculation for the desorber can account for different design configurations where adiabatic sorption processes may occur (e.g. sprayed or irrigated heat exchangers, case A) or not (e.g. 
flooded heat exchangers, case B). In addition to the differentiation into case A and B  there are three possibilities for the heat transfer calculation in ab- and desorber:
a) case A or B with temperature independent heat capacity flow rate,
b) case A or B with linear temperature dependent heat capacity flow rate,
c) case A or B with arbitrary temperature dependent heat capacity flow rate (cell method)
Variable internal and external flow rates are possible. But only for the external flow rates the heat transfer coefficients are adapted according to the method described in subsection 2.3.6 of the phd. In parallel to the internal cycle simulation combined with the heat transfer calculation the established and enhanced method of characteristic equations is applied (cf. chapter 3 of the phd). The results of the cycle simulation are plotted in a p-T-diagram and h-xi-diagram. Additional plots which compare the simulated heat flows in evaporator and desorber to the results derived from established and enhanced method as function of the characteristic temperature difference DDt are provided.
 
GETTING STARTED: 
To run the programm you need to have access to the following LIB- and ZIP-files also:
1) CE_Method_20190724ja.LIB      \
2) CE_Method_FDL_files.zip        |  http://dx.doi.org/10.14279/depositonce-8707 
3) ZAKA_20190726ja.LIB           /
4) H2OLiBr_GF.LIB                   http://dx.doi.org/10.14279/depositonce-8709
All these files are available at DepositOnce. Copy the three LIB-files into your userlib-folder (e.g. c:\Users\me\EES32\Userlib\MyLibs\). Unzip the ZIP-file with the FDL-files into the same folder. Close all EES-files and (re)open AKA_CE_Simulation.EES. When everything is correct and you press F2 the simulation should start calculating the nominal operating point of chiller type FA2. If you add comment brackets arround the external inlet temperature in section 2 'External operating conditions' (i.e. change line 'tex_Di = 75; tex_Ai  = 27; tex_Ei  = 18;' to '{ tex_Di  = 75; tex_Ai  = 27; tex_Ei  = 18; }' the table '01_FA2_AA' can be calculated by pressing F3.