{"references": ["Montreal protocol on substances that deplete the ozone layer. United Nations Environment programme (UNEP), 1987.", "H.M. Getu, P.K. Bansal Thermodynamic analysis of an R744\u2013R717 cascade refrigeration system, International Journal of Refrigeration, 31(2008), pp. 45-54.", "J. Alberto Dopazo, Jos\u00e9 Fern\u00e1ndez-Seara , Jaime Sieres and Francisco J. Uh\u00eda Theoretical analysis of a CO2\u2013NH3 cascade refrigeration system for cooling applications at low temperatures, Applied Thermal Engineering, 29 (2009), pp.1577\u20131583.", "Devanshu Pyasi, R.C. Gupta, Performance analysis of 404a/508b Cascade Refrigeration cycle for low Temperature, International Journal of Engineering Science and Technology, 3(2011), pp.6501-6507.", "Tzong-Shing Lee, Cheng-Hao Liu, Tung-Wei Chen, Thermodynamic analysis of optimal condensing temperature of cascade-condenser in CO2/NH3 cascade refrigeration systems, International Journal of Refrigeration 29 (2006), PP.1100-1108.", "A.D. Parekh and P. R. Tailor, Thermodynamic Analysis of R507A-R23 Cascade Refrigeration System, International Journal of Aerospace and Mechanical Engineering 6:1, 2002.", "Souvik Bhattacharyya, S. Bose, J. Sarkar, Exergy maximization of cascade refrigeration cycles and its numerical verification for a transcritical CO2-C3H8 system, International Journal of Refrigeration 30 (2007), PP.624-632."]}

The Montreal protocol and Kyoto protocol underlined the need of substitution of CFC’s and HCFC’s due to their adverse impact on atmospheric ozone layer which protects earth from U.V rays. The CFCs have been entirely ruled out since 1995 and a long-term basis HCFCs must be replaced by 2020. All this events motivated HFC refrigerants which are harmless to ozone layer. In this paper thermodynamic analysis of cascade refrigeration system has been done using three different refrigerant pairs R13-R12, R290-R23, and R404A-R23. Effect of various operating parameters i.e. evaporator temperature, condenser temperature, temperature difference in cascade condenser and low temperature cycle condenser temperature on performance parameters viz. COP, exergetic efficiency and refrigerant mass flow ratio have been studied. Thermodynamic analysis shows that out of three refrigerant pairs R12-R13, R290-R23 and R404A-R23 the COP of R290-R23 refrigerant pair is highest.