Performance evaluation of a solar absorption refrigerator for tomatoes pre-cooling

Abstract EN

n 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.