Methods for Improving Thermal Performance of Three Stage Vapour Compression Refrigeration Systems with Flash-Intercooler Using Energy- Exergy Analysis of Eight Ecofriendly Refrigerants

The exergy analysis is a powerful tool for finding irreversibilities occurred in the components as well as complete system. Global warming and ozone depletion is a big issues for saving our environment. In this paper using first law and second law analysis , the comparison of eight environmental friendly refrigerants on multiple stage vapour compression refrigerator with flash intercooler and individual throttle valves (system-1) and multiple stage vapour compression refrigerator with flash intercooler and multiple throttle valves (system-2) has been carried out. For eight selected refrigerants irreversibilities occurred in the system -1 is higher than the system-2 and first law efficiency (COP) and exergy efficiency of system-1is lower than sytem-2.The Exergetic performance of R600 and R717 is better in comparison of other selected ecofriendly refrigerants for both systems where as ecofriendly R125 refrigerant showed lowest thermal performances in terms of COP (energetic efficiency), and exergetic efficiency (second law efficiency) and higher irreversibilities in terms of exergey destruction ratio (EDR) . As ecofriendly R717 refrigerant is toxic in nature and restricted to limited applications and hydrocarbon R600 is slightly lower performance than R717 and 2-3% higher performance than R134a refrigerant is also flammable in nature can be used without taking of any safety precautions.Therefore R134a may also be used for practical applications. Also R134A is easily available, The performance of R1234yf (GWP four with zero ozone depletion potential) gives lower thermal performance than R134a