Improved energy efficiency for CFC domestic refrigerators retrofitted with ozone-friendly HFC134a/HC refrigerant mixture

摘要

Conversion of CFC12 systems to eco-friendly ones will be a major thrust area for refrigeration sector in the near future. As and when an existing CFC (chlorofluorocarbon) system has to be recharged it is advisable to retrofit the system with an eco-friendly energy efficient refrigerant. Presently two potential substitutes, namely, HFC134a and HC blends are available as drop in substitutes for CFC 12. HC (hydrocarbon) refrigerants do have inherent problems in respect of flammability. HFC134a is neither flammable nor toxic. But HFCs (hydrofluorocarbons) are not compatible with mineral oil and the oil change is a major issue while retrofitting. The above techno-economic feasibility issue to retrofit the existing CFC 12 systems with ozone friendly refrigerant and the energy efficiency of the system are the challenges in the domestic refrigeration sector. In this present work an experimental analysis has been carried out in a 165 1 CFC 12 household refrigerator retrofitted with eco-friendly refrigerant mixture of HFC134a/HC290/HC600a without changing the mineral oil. Its performance, as well as energy consumption, is compared with the conventional one. As the system has been running successfully for more than 12 months it is also evident that the new mixture is compatible with mineral oil. It has been found that the new mixture could reduce the energy consumption by 4 to 11% and improve the actual COP by 3 to 8% from that of CFC 12. The new mixture also showed 3 to 12% improvement in theoretical COP. The overall performance has proved that the new mixture could be an eco-friendly substitute to phase out CFC 12.