Optimum design of a solar ejector refrigeration system for various operating scenarios

Abstract

The objective of this work is to examine a solar ejector refrigeration system under various operating scenarios. Evacuated tube collectors of 100 m2 collecting area coupled to a storage tank of 4 m3 are selected for feeding the generator of the refrigerator. The system is examined for different evaporator temperatures from −10 °C to 10 °C and for different heat rejection temperatures from 30 °C to 50 °C. In every case, the system is optimized by selecting the optimum ejector design and the optimum generator temperature. Different refrigerants are examined as R123, R245fa, R600a and R134a, while the emphasis is given to the R141b. The innovation of this work is based on the systematic examination and optimization of a great range of operating scenarios giving a clear image for the system performance. According to the final results, the R141b is found to be the best candidate in all the operating scenarios. More specifically, the maximum system COP is found to be 0.234 when the system produces refrigeration at 10 °C and rejects heat to the environment at 30 °C. The optimum generator temperatures are found to be from 114 °C to 157 °C and the cooling capacity is ranged from 1.85 kW up to 23.39 kW. The analysis is performed with a developed model in EES (Engineering Equation Solver) under steady-state conditions.