Abstract:
This experimental study investigated the energy and exergy performance of R32/R600a (50:50 by mass)
with TiO2 nanofluid for a residential air conditioning system which was originally designed for R22.
R32/R600a has been used along with 0.01%-0.02% volume concentration TiO2
nanolubricant. Cetyl
trimethylammonium bromide (CTAB) has been used as surfactant. Pressures and temperatures of
different components have been recorded for measuring energy and exergy parameters. RERPROP 7
software has been used to determine the thermal properties of the refrigerants and the blend at different
conditions. The results show that the R32/R600a has lower value of COP compared to R22. Numerically
R32/R600a blend has 32%, blend with 0.01% nanofluid has 26% and blend with 0.02% nanofluid has
61% less COP than R22. However, refrigerating effect of the blend has increased by 10 percent compared
to R22 while the blend with 0.01% and 0.02% has 20% and 9% more refrigerating effect respectively.
Again, the blend without nanofluid and along with nanofluid (0.01%, 0.02%) have 25%, 7% and 3%
more power consumption than that of R22 respectively. Exergy analysis shows R32/R600a blend and the
0.01%, 0.02% nanofluid have higher irreversibility compared to R22. Overall, R32/R600a blend is not
suitable for retrofitting in R22 system.
