Document Type : Original Article


Agric. Eng. Dept., Fac. Agric., Zagazig Univ., Egypt


In this study, an ammonia-water absorption refrigerator (AWAR) with 50 L in
capacity was operated by solar energy captured by two systems for conducting tomatoes pre-cooling
process particularly in hot weather. The first system was a solar photovoltaic-thermal system which
consisted of flat plate solar collector combined with the photovoltaic (PV) system, while, the second
system included the solar photovoltaic (PV) system solely. This study aims to evaluate the performance of
the solar absorption refrigerator with load and without load under Egyptian climatic conditions to
investigate the capability of AWAR to perform tomatoes pre-cooling and reach the recommended
range of tomatoes cold storage in the cooling cabinet (7-10°C) because tomatoes is perishable product.
The obtained results indicated that using the solar photovoltaic-thermal absorption refrigerator
(SPTAR) at hot water flow rate of 1.58 L/min and cooling load of 23 Kg of tomatoes (maximum
capacity) gave the highest values of refrigeration system’s coefficient of performance (COPref) of 0.30
and cooling cabinet temperature of 284 °K/11°C at the lowest temperature of evaporator (272°K/-
1°C). Nevertheless, solar photovoltaic absorption refrigeration system (SPAR) gave lower COPref
value of 0.27 and temperatures in the cooling cabinet of 295°K/22°C and evaporator temperature of
285°K/12°C at PV efficiency of 11% Hence, the integration of the flat plate solar collector with the
PV system in SPTAR as heating system for the generator led to an enhancement in the performance of
the AWAR at the maximum capacity of the refrigerator comparing to using the PV panels solely in
SPAR system. Ultimately, using SPTAR system may reduce the operating times of the electric
heater and consequently using less numbers of solar batteries for long operating time with low
constructional cost.