Performance of R-22 and its Alternatives Working at High Outdoor Temperatures

摘要

This paper examines the performance of r-22 and its possible replacements in an air-cooled air conditioner. The study focues on the effect of Elevated outdoor temperatures on system capacity and coefficient of performance (COP). The refrigerants considered are R-22, R-134a, R-290, R-410a and r-407c> Relative metris of these fluids are evaluated using the UA version of NIST'S semi-theoretical vapr-comppression model CYCLE-11. The study includes performance results for the basic cycle and for the cycle with a liquid-line/suction-line heat exchanger. The examined refrigerants exhicit avring degradations in performance at elevated temperatures compared to their performance at a typical operating regime. Different refrigerants' critical temperatures and differences in the shape of the two-phase dome on the temperature-entropy diagram can explain different performance trends for the refrigerants studied.