IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration Subtask C2-A, November 9, 2009
1. Modelling of the solar desiccant cooling installation
A model implementation of a desiccant cooling installation powered by vacuum tube solar
collectors in SPARK is described in this section. The Desiccant wheel, the sensible
regenerator and the evaporative cooler are selected from bibliography. However a new
developed model of the vacuum heat pipe solar collectors is presented.
The aim of this implementation is to predict accurately the supply conditions of a desiccant
air handling for different operating conditions and to predict the real potential of solar energy
in this process.
Nomenclature
Symbols
c pa heat capacity of air [J.kg -1 .K -1 ]
c pv heat capacity of water vapor [J.kg -1 .K -1 ]
c pm heat capacity of the regenerator matrix [J.kg -1 .K -1 ]
C min min capacitance rate of the regenerator inlet fluids [J.s -1 .K -1 ]
C r parameter used in the correlation of the regenerator [-]
e thickness [m]
F i potential characteristic [-]
G solar global radiation [W. m -2 ]
h heat transfer coefficient [W.K -1 m -2 ]
h a enthalpy of moist air [J.Kg -1 ]
h fg
latent heat of vaporization [J.kg]
H enthalpy of the sensible or desiccant regenerator matrix [J.Kg -1 ]
J t lumped heat transfer coefficient [s -1 ]
J m lumped mass transfer coefficient [s -1 ]
K heat loss constant [W.K -1 m -2 ]
L width of the desiccant wheel [m]
L v latent heat of vaporization of the heat pipe fluid [J.kg -1 ]
Le Lewis number [-]
m a air mass flow rate [Kg.s -1 ]
M mass [kg]
M d
M m
mass of the desiccant matrix [Kg]
mass of the aluminium matrix [Kg]
N angular speed of the wheel [rd.s -1 ]
Na number of nodes in the angular direction of the desiccant wheel [-]
Np number of nodes in the width direction of the desiccant wheel [-]
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