EXPERIMENTAL RESULTS OF TRANSCRITICAL CO{sub}2 REFRIGERATOR USING AN AIR COOLING EVAPORATOR

摘要

Chlorofluorocarbons (CFCs) have been phased out and hydroclorofluorocarbons (HCFCs) are in process of being phased out as refrigerants due to their potential to destroy the ozone layer of the earth's atmosphere. Carbon dioxide (CO{sub}2) is non-toxic, non-flammable, has zero ozone depletion potential and negligible global warming potential as a refrigerant. The main purpose of this study is to investigate about the energetic performances of a transcritical CO{sub}2 refrigerator working as a classical "split-systems" to cool air in residential applications. The design and construction of the refrigerator is shown and experimental results of investigations carried out are presented. The CO{sub}2 system utilizes aluminium heat exchangers, a semi-hermetic compressor, an expansion valve and a suction line heat exchangers. The performances measured in terms of Coefficient of Performances show a decrease respect to the "split-system" working with the HCFCs at the same external ed internal conditions. Further improvements regarding the components of the cycle are necessary to use in large scale the "split-systems" working with the carbon dioxide.