Optimizing R152a/R600 and R290/R600 mixtures for superior energy performance in vapor compression systems: Promising alternatives to Isobutane (R600a)

This study presents an experimental investigation into the optimal composition of R152a/R600 and R290/R600 mixtures as potential alternatives to isobutane (R600a) in a single-stage vapor compression cycle. The research involved testing eight different mass compositions for R152a/R600 and ten mass compositions for R290/R600, comparing their performance with that of R600a. After careful analysis, the " optimum " mass compositions were identified as (10/90)% for both R152a/R600 and R290/R600, achieving a balanced trade -off among coefficient of performance (COP), volumetric cooling capacity (VCC), and cooling output ( (center dot) Q o ). Further tests were conducted on the " optimum " compositions at nine different secondary fluid temperature inlets. The results indicated an average COP increase of + 7.3 % for the R152a/R600 mixture, with decreases of -11.4 % in VCC and -9.7 % in (center dot) Q o . Similarly, the R290/R600 (10/90)% mixture showed a COP increase of + 10.3 %, accompanied by VCC and (center dot) Q o decreases of -8.8 % and -6.6 %, respectively. Notably, both mixtures exhibited superior energy performance compared to isobutane while maintaining similar thermodynamic properties, particularly the R290/R600 (10/ 90)% mixture. These findings suggest that the R152a/R600 and R290/R600 mixtures could serve as long-term, high-efficiency alternatives to R600a in vapor compression cycles.