Thermodynamic analysis of two dual-purpose compression refrigeration systems with environmentally friendly refrigerants in different climates

The present research investigates the thermodynamics of two dual-purpose condensation refrigeration systems, including a system with a flash-chamber and a cascade refrigeration system used in cold storages with the aim of providing two temperature ranges above zero and below zero. The purpose of this research is to investigate the annual energy consumption of dual-purpose refrigeration systems with environmentally friendly refrigerants and also to investigate the parameters affecting the efficiency of these systems. Results show that the best refrigerant in terms of performance in both refrigeration systems is R290. The system with a flash-chamber has a higher efficiency, and its energy consumption is 30% lower in hot and humid areas and almost 20% lower in other climates than the cascade system. Also, it was found that flash-chamber system has more limitations than the cascade system, and many refrigerants cannot be used in it due to pressure limitations. The comparison of these two systems shows that with the assumption that the total load capacity of the cold storage is constant, the energy consumption of both systems increases with the increase of the thermal load of the sub-zero evaporator.