This paper deals with the evaluation of the Coefficient of Performance (COP)
of solar adsorption refrigeration. In the literature, simulation models to predict
the thermal behaviour and the coefficient of performance of these systems
are uncommon. This is why we suggest a model to simulate the operation
of the machine in a typical hot and dry climate of the city of Ouagadougou.
The objective is to provide a model for calculating the COP from the
measurement of the ambient temperature and the irradiation of a given site.
Starting from mathematical modelling, a resolution and simulation were made
with COMSOL software based on the Dubinin-Astakhov adsorption model,
the heat transfer balance equations, and the Linear Driving Force (LDF) model
to describe the thermal behaviour of the system. A one-week measurement
sequence on the adsorption solar refrigerator at the Albert Schweitzer Ecological
Centre (CEAS) validated the numerical results. The measurement
shows that for the days with high sunshine, the temperature of the reaction
medium reaches 110˚C, and the pressure reaches 500 mbar. This leads to a
production of cold that allows it to reach the temperature of −5˚C at the
evaporator. Under these conditions, the COP is worth 14%. These results are
obtained both by numerical simulation using the COMSOL 5.1 software and
after a measurement session on the solar refrigerator available to the CEAS.
We obtained an experimental and theoretical coefficient of performance varying
between 9% and 14% with a difference of between 0% and 3%. We conclude
that our model is suitable to estimate the COP of any device based on
its thermal properties, the ambient temperature and the irradiation of a given
site.

Solar Refrigeration Adsorption Coefficient of Performance Modelling