Thermodynamic performance enhancement of booster assisted ejector expansion refrigeration systems with R1270/CuO nano-refrigerant

Abstract

Ejector expansion refrigeration systems have gained prominence in the refrigeration sector, providing much better thermodynamic performance than conventional refrigeration systems. The present work aims to improve the thermodynamic performance of a booster assisted ejector expansion vapour compression refrigeration system with constant area mixing theory for low-temperature applications using R1270/CuO nano-refrigerant. Comparative energy and exergy based thermodynamic analysis of pure refrigerant and nano-refrigerant (2 wt% of CuO to R1270) systems are carried out. The pressure drop in the receiver part of the ejector and pressure ratio of the booster compressor are optimized for different operating conditions. The optimized results pointed out that the system using nano-refrigerant is the best one for which the proposed system has 8% lower discharge temperature of the main compressor, 0.59% lower ejector area ratio, 3.23% lower entrainment ratio, 8.93% higher exergy efficiency, 8.96% higher COP (Coefficient of Performance) and 21.23% lower total exergy destruction than pure refrigerant-based system at a condenser temperature of 45 °C and an evaporator temperature of −30 °C. Furthermore, there is a minimum COP improvement of 14.42% and a maximum COP improvement of 29.32% compared to research studies in the literature under identical operating conditions. The proposed calculation procedure has maximum deviation of 4.17% compared to experimental studies in the literature. Therefore, it can serve as a useful guide for performing the theoretical analysis of nano-refrigerant based ejector expansion refrigeration systems before setting up an experimental system.