A THEORETICAL COMPARISON OF TWO ECO-FRIENDLY REFRIGERANTS AS ALTERNATIVES TO R22 USING A SIMPLE VAPOUR COMPRESSION REFRIGERATION SYSTEM

The paper presents a theoretical investigation into the performance of R432A and R433A refrigerants as alternatives to the ozone depleting R22 refrigerant. The two refrigerants have zero ozone depleting potential and a negligible global warming potential. The results obtained showed that the properties of the three investigated refrigerants are similar. The saturation vapour pressures for R432A and R433A, between the saturation temperatures of -30 to 40 degrees C, are 99.6 and 99.3% the same as that of R22. The performance of R22 in terms of power per ton of refrigeration (PPTR), volumetric refrigeration capacity (VRC) and coefficient of performance (COP) is slightly better than the performance of the two alternative refrigerants. The average COPs obtained for R432A and R433A were lower by only 4.5 and 5.4%, respectively, than those of R22, but the two alternative refrigerants equally exhibited better pressure ratios, discharge temperatures and pressures than R22. Both R432A and R433A have higher refrigerating effects than R22. The VRC and COP of R432A are higher by 3.8% and 0.9%, respectively, than those of R433A. Generally, the performance of the two alternative refrigerants is quite similar in all operation conditions and they have shown satisfactory performance as good long term alternatives to R22 refrigeration systems.