Volume 10 Issue 1 ( March 2023 )

In this paper, irreversibility analysis of an ejector refrigeration system (ERS) is carried out using modified Gouy- Stodola formulation that incorporates the use of an effective temperature unlike the surrounding temperature employed in classical Gouy-Stodola equation for the irreversibility determination. The components of any system do not transfer heat at surrounding temperature all the times and thus some error is involved in the analysis, as the conventional equation calculates irreversibility using the surrounding temperature. The use of effective temperature provides more accurate measurement of exergy destruction. R1234ze is the refrigerant in this study due to its low Global Warming Potential (GWP) and zero Ozone Depletion Potential (ODP) and is compared with its counterpart R134a. The study is conducted for a fixed 10 kW cooling system. The coefficient of performance (COP) is found to increase by 15.93% and 11.68% for R1234ze and R134a respectively with the change in generator temperature from 91°C to 99°C. However, the drop in COP is 52.38% and 58.54% for R1234ze and R134a respectively with increase in condenser temperature from 32°C to 40°C. It shows that R1234ze performs better than R134a. Due to the highest coefficient of structural bonding (CSB) value in the evaporator, the change in total irreversibility is particularly susceptible to changes in evaporator temperature.

Keywords: Exergy, irreversibility, effective temperature, ejector refrigeration system, coefficient of structural bonds.