A comprehensive study on 21st-century refrigerants-R290 and R1234yf: A review

Prolonged use of environment unfriendly refrigerants in high-grade energy systems has resulted in increased greenhouse gas emissions and ozone layer depletion. This has resulted in increased global warming. Therefore, it is important to analyze all the studies of any refrigerant before its use for the sustainable development of any system. The present review paper is an attempt to report all studies related to 21st century refrigerants comprising sustainable refrigerants for longer use. In this regard, the historic evolution of refrigerants and their potential effect on global warming and ozone layer depletion are presented. Further, R290 and R1234yf are found to be promising alternatives amongst all refrigerants to be used as 21st-century refrigerants. An attempt has been made to provide a comprehensive study for these refrigerants, including their thermophysical properties, leakage in the compressor, leakage in the evaporator, leakage in the condenser, explosion characteristics due to leakage, and consequences due to leakage and explosion. In addition, a thorough study has been made for the use of oils, their importance, and their consequences in a refrigeration system. The study has also been made for the use of these refrigerants in flow boiling and condensation. The increased commercialization of electric vehicles and refrigerant use in electric vehicles may increase global warming in near future. Therefore, the discussion has been included to use these refrigerants in electric vehicle air conditioning systems. Finally, a short conclusion with the future scope is presented for the various aspect of 21st-century refrigerants. (c) 2021 Elsevier Ltd. All rights reserved.