3473 -- Air-to-Air Heat Pump Performance with Three Different Nonazeotropic Refrigerant Mixtures PDF

Describes experimental tests using a conventional air-to-air heat pump with nonazeotropic refrigerant mixtures operating over a range of outdoor temperatures between 1.8degC (35degF) and 35.2degC (95degF). Three different two-component mixtures were selected - R22/R114, R13/R12, R22/R152A. Finds that favourable mixture thermodynamic properties enhanced the performance of the R22/R152A mixture compared to the pure R22. At a 15% R152A concentration the coefficient of performance increased by at least 8% without a significant loss in capacity, less than 4% compared to pure R22. States that the primary reason for a degradation in system efficiency for the other mixtures was due in part to the crossflow design of conventional air-to-refrigerant heat exchangers.

KEYWORDS: Heat pumps, air air heat pumps, refrigerants, mixtures, non azeotropic, performance, efficiency, coefficient of performance, thermodynamics, heat exchangers, cross flow heat exchangers, R22, R114, R12, R152a, R13