International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print), ISSN 0976 – 6359(Online), Volume 6, Issue 1, January (2015), pp. 71-91 © IAEME 71 SIMULATION OF THERMODYNAMIC ANALYSIS OF CASCADE REFRIGERATION SYSTEM WITH ALTERNATIVE REFRIGERANTS Mr. PARTHIBAN KASI Assistant Professor, Department of Mechanical Engineering, Velammal Institute of Technology, Chennai, India ABSTRACT The main aim of this project is to analyses the cascade refrigeration system by employing various alternative refrigerant pairs and choosing the best pair for higher temperature circuit (HTC) and lower temperature circuit (LTC). The analysis was done in various refrigerants pairs which are R134a/R23, R290/R23, R404A/R23, R407C/R23, R410A/R23, R134a/R508B, R290/R508B, R404A/R508B, R407C/R508B, R410A/R508B, R134a/R170, R290/R170, R404A/R170, R407C/R170 and R410A/R170. Assuming the degrees of sub cooling and superheating as 5°C and 10°C, respectively. The condenser temperature in higher temperature circuit (HTC) was varied from 30°C to 50°C and evaporator temperature in lower temperature circuit (LTC) was varied from -70 to -50°C. The intermediate heat exchanger temperature is about -20°C. Furthermore, the efficiencies of the compressors are assumed to be equal as 0.7. It has been found that the coefficient of performance (COP) of the cascade refrigeration system increases and the mass flow rate of higher temperature circuit increases, along with the work of compressor with rise in evaporator temperature for all refrigerant pairs. On the other hand, the COP of the cascade refrigeration system decreases and the mass flow rate of higher temperature circuit increases, also there is increase in work of compressor with increase in condenser temperature. Finally, the refrigerant pair R134a–R170 has the highest COP and lowest mass flow rate, while R404A–R508B has the lowest COP and highest mass flow rate. Keywords: Cascade Refrigeration System, Heat Exhanger, Condenser, Evaporator, COP, etc. 1. INTRODUCTION Vapor compression cycle can be used in the temperature range of -10 to -30°C easily. And low-temperature refrigeration systems are typically required in the temperature range from –30°C to – 100°C for applications in food, pharmaceutical, chemical, and other industries, e.g., blast freezing, INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING AND TECHNOLOGY (IJMET) ISSN 0976 – 6340 (Print) ISSN 0976 – 6359 (Online) Volume 6, Issue 1, January (2015), pp. 71-91 © IAEME: www.iaeme.com/IJMET.asp Journal Impact Factor (2014): 7.5377 (Calculated by GISI) www.jifactor.com IJMET © I A E M E