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Due to the impact of global warming and climate change, more and more people are starting to have a clearer understanding and vigilance about greenhouse gases. To prevent further deterioration of the global environment, this study examines the coefficients of performance of 21 currently available refrigerants with very low global-warming potential and zero ozone-depleting potential under evaporation temperatures of 10, −20, −40, and −60 °C and condensation temperatures of 30, 40, and 50 °C, respectively. It is found that the use of pure refrigerant in a two-stage refrigeration system to replace the single-stage refrigeration system, in addition to mixing it into an appropriate mixture, can effectively improve the performance coefficient of the refrigeration system. For single-stage vapor compression refrigeration systems, R1234ze(Z), R601, and R1233zd(E) have the best refrigeration performances among the environmentally friendly refrigerants studied, while R441A performs the worst for Teva = 10 °C and −20 °C. Moreover, RE170 has the highest COP of the refrigeration system for Teva = −40 °C and −60 °C. However, R1234yf performs worse in COP when the evaporation temperature is lower, and it ranks last for Teva = −60 °C. When a double-stage vapor compression refrigeration system is employed instead, the percentage increase in the COP of the system using R1234yf becomes the largest for Teva = −40 °C and −60 °C. However, the growth rate of R717 ranks last for Teva = −60 °C. For an R717/R1234yf mixture at an optimum mass fraction of 0.25, the COP of the refrigeration system can be increased up to 25.8% despite an increase of 15.2% in operating pressure compared to R1234yf. The discharge temperature may rise; however, there will be no overheating problem for the compressor. [ABSTRACT FROM AUTHOR]

Environmental concern is the major issue faced in refrigeration and air conditioning systems. The performance of a refrigeration system can be altered through altering the system or changing the properties of working fluids such as refrigerants. Traditionally, CFC is widely used as a refrigerant in refrigeration systems. But this CFC refrigerant has high ODP and GWP value. So, other refrigerants such as HCFC and HFC is developed as an alternative to CFC refrigerant. However, this refrigerant also haVE high GWP values. So, the researchers are focused on designing an effective-refrigerant that reduce the emission due to usage of reduced power consumption. Recently, the use of Nanoparticles had gained attention in many engineering fields due to its excellent properties. This review article summarizes the use of different nanorefrigerant in the refrigerant system along with its performance. Initially, this article covers the use of traditional refrigerants Such as CFC. After that, the use of conventional refrigerants such as HCFC and HFC as a substituent for CFC is displayed. After that integration of Nanoparticles along with conventional refrigerant for performance-improvement is studied. Following that various Nanoparticles such as TiO2, SiO2 and CuO dispersed along with conventional refrigerant are also studied. The analysis is done through evaluating the performance of nanorefrigerant based on COP and Power consumption. Analysis showed that the application of Nanoparticles along with refrigerant attains better performance in comparison with conventional refrigerant. Ultimately, the difficulties and possibilities for further study are highlighted, which will be helpful for the field's newcomers and manufacturers. [ABSTRACT FROM AUTHOR]