PERFORMANCE EVALUATION OF A SOLAR ABSORPTION REFRIGERATOR FOR TOMATOES PRE-COOLING

Abstract

In this study, an ammonia-water absorption refrigerator (AWAR) with 50 L incapacity was operated by solar energy captured by two systems for conducting tomatoes pre-coolingprocess particularly in hot weather. The first system was a solar photovoltaic-thermal system whichconsisted of flat plate solar collector combined with the photovoltaic (PV) system, while, the secondsystem included the solar photovoltaic (PV) system solely. This study aims to evaluate the performance ofthe solar absorption refrigerator with load and without load under Egyptian climatic conditions toinvestigate the capability of AWAR to perform tomatoes pre-cooling and reach the recommendedrange 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 (maximumcapacity) gave the highest values of refrigeration system’s coefficient of performance (COPref) of 0.30and 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 COPrefvalue of 0.27 and temperatures in the cooling cabinet of 295°K/22°C and evaporator temperature of285°K/12°C at PV efficiency of 11% Hence, the integration of the flat plate solar collector with thePV system in SPTAR as heating system for the generator led to an enhancement in the performance ofthe AWAR at the maximum capacity of the refrigerator comparing to using the PV panels solely inSPAR system. Ultimately, using SPTAR system may reduce the operating times of the electricheater and consequently using less numbers of solar batteries for long operating time with lowconstructional cost.