| dc.description.abstract | Diϱusion absorption refrigeration (DAR) is a reliable cooling system, especially in
conditions where conventional refrigeration systems are not convenient. Since it operates
without any mechanical components, the DAR refrigerator is silent, making it suitable for
quiet environments. The evaporation process in DAR systems notably aϱects their operation.
However, few studies have focused on this speciϧc issue. In this work, a numerical
investigation was conducted using CONVERGE CFD software and the RANS approach to
analyze the evaporator region of a DAR system operating with an ammonia/water mixture
and using hydrogen or helium as an inert gas. The aim was to validate an accurate CFD model
by analyzing the ϩow behavior and thermal parameters within the evaporator for an
ammonia/hydrogen gas mixture ϧrst, and then to examine the use of helium instead of
hydrogen as the pressure equalizer. For this purpose, an experimental bench was prepared.
The computational results showed high agreement with the experimental data, with slight
deviations often remaining under 3%. The study also investigated the eϱect of ammonia
presence at the hydrogen inlet, speciϧcally at 5% and 10% ratios. The results demonstrated
that the average temperature deviation was less than 1% when using 5% ammonia. A total
pressure of 5 bars was found to be appropriate for the DAR system when helium replaces
hydrogen. This study sheds light on the evaporation process, which is crucial for enhancing
the design and operational eϫciency of DAR systems. The validated numerical model will be
of great use for this purpose. | en_US |