R407C AS AN ALTERNATIVE TO R22 IN VAPOR COMPRESSION PLANT - AN EXPERIMENTAL-STUDY

The problem of HCFC22 phase-out in refrigeration plants is analysed, A comparison is performed between R22 and R407C, The latter seems a pro mising drop-in substitute. Indeed, its use in existing plants would on ly require discharge of mineral oil and refilling with a compatible po lyolester oil. The experimental tests are performed in a plant consist ing in a water-cooled vapor-compression circuit employed for cooling a water-glycol mixture in a closed-loop system. Both the thermodynamic properties and general performance of R407C are comparable with those of R22. The COP, however, is 5-17% lower, As a consequence, in order t o provide the same refrigerating load, a plant working with R407C requ ires higher electric-power consumption. The operational behaviour of R 407C is increasingly better with increasing condensation and evaporati on temperature. Therefore, R407C is a good R22 substitute in all appli cations requiring high evaporation temperatures, such as air-condition ing plants. (C) 1997 by John Wiley & Sons, Ltd.