Performance evaluation of environmentally benign refrigerants in heat pumps 2: An experimental study with HFC134a

The performance characteristics of HFC134a in an industrial (water to water) heat-pump test facility at Electricité de France with a twin-screw compressor are presented. The performance of HFC134a has been studied in terms of performance parameters of the compressor (e.g. its volumetric and isentropic efficiencies) and of the heat-pump system (e.g. coefficient of performance and volumetric heating capacity) with a view to using it in new installations for low to medium temperature (< 70°C) applications as well as to replacing CFC12 in existing installations. The influence of degree of superheat on the miscibility of HFC134a with ester oil and on the viscosity of the oil-refrigerant mixture has also been studied for various discharge pressures.